This document discusses the effect of heating rate on the structural and optical properties of silicon and magnesium co-doped zirconia nanopowders prepared by a sol-gel method. X-ray diffraction analysis showed that different heating rates between 1-10°C/min affected the formation of tetragonal and cubic phases, crystallinity, and particle size. Ultraviolet-visible spectroscopy showed that the band gap energy of the doped zirconia crystals decreased depending on the heating rate, with a minimum band gap of around 3-3.2 eV.
Preparation, Structure, and Characterization of Nd2mo2o9 fast Oxide Ion Condu...IJARIIT
The structure and ion conductivity of Nd2Mo2O9powders were synthesized by using Nd(NO2)3, MoO3, and aspartic acid (fuel) in assisted combustion method with heating at 550˚C for 6 hours. The thermal decomposition, phase identification, morphology, ionic conductivity of the samples were studied by TGA/DTA, XRD and SEM four probe D.C. method respectively. The formation of Nd2Mo2O9 was confirmed by FTIR studies. The synthesis and crystallization were followed by thermochemical techniques (TGA/DTA) studies. The synthesized materials showed reasonable ionic conductivity. These results indicate that assisted combustion method is a promising method to prepare nanocrystalline Nd2Mo2O9 for solid oxide fuel cell.
Synthesis Of Nanostructured TiO2 Thin Films By Pulsed Laser Deposition (PLD) ...sarmad
Sarmad Sabih Al-Obaidi
Ali Ahmed Yousif
Abstract
In this work, nanostructured TiO2 thin films were grown by pulsed laser deposition (PLD) technique on glass substrates. TiO2 thin films then were annealed at 400-600 °C in air for a period of 2 hours. Effect of annealing on the structural and morphological were studied. Many growth parameters have been considered to specify the optimum conditions, namely substrate temperature (300 °C), oxygen pressure (10-2 Torr), laser fluence energy density (0.4 J/cm2), using double frequency Q-switching Nd:YAG laser beam (wavelength 532nm), repetition rate (1-6 Hz) and the pulse duration of 10 ns. The results of the X-ray test show that all nanostructures tetragonal are polycrystalline. These results show that grain size increase from 19.5 nm to 29.5 with the increase of annealing temperature. The XRD results also reveal that the deposited thin film, annealed at 400 °C of TiO2 have anatase phase. Thin films annealed at 500 °C and 600 °C have mixed anatase and rutile phases. Full Width at Half Maximum (FWHM) values of the (101) peaks of these films decrease from 0.450° to 0.301° with the increase of annealing temperature. Surface morphology of the thin films have been studied by using atomic force microscopes (AFM). AFM measurements confirmed that the films have good crystalline and homogeneous surface. The Root Mean Square (RMS) value of thin films surface roughness are increased with the increase of annealing temperature.
الخلاصة
على (PLD) النانویة بوساطة تقنیة ترسیب اللیزر النبضي (TiO في ھذا البحث، تم انماء أغشیة اوكسید التیتانیوم ( 2
الرقیقة من 400 الى 600 درجة مئویة في الھواء مدة ساعتین . ودرس تأثیر TiO قواعد زجاجیة. ومن ثم لدنت أغشیة 2
التلدین في الخصائص التركیبیة والطبوغرافیة. عوامل عدیدة لأنماء الأغشیة اخذت بنظر الاعتبار لتحدید الحالة المثلى مثل
0.4 ) باستخدام J/cm 10-2 ) ،كثافة طاقة الفیض اللیزري( 2 Torr) 300 ) ،ضغط الأوكسجین ºC) درجة حرارة القاعدة
532 بمعدل تكراریة - 1 nm التردد المضاعف للیزر النیدیمیوم- یاك الذي یعمل بتقنیة عامل النوعیة عند الطول الموجي
6 ھرتز) وامد نبضة 10 نانوثانیة. تظُھر نتائج فحوصات الأشعة السینیة أن جمیع التراكیب النانویة رباعیة متعددة )
التبلور. وان ھذه النتائج تظھر زیادة في حجم الحبیبات من 19.5 نانومتر الى 29.5 نانومترمع زیادة درجة حرارة التلدین.
نتائج الأشعة السینیة اظھرت ایضا ان الغشاء المرسب والملدن في 400 درجة مئویة لثنائي اوكسید
Synthesis and charaterization of la1 x srxmno3 perovskite nanoparticlesMai Trần
In recent times perovskite materials are extensively studied and have attracted much attention because they exhibit interesting the properties, showing potential applications in commercial, technical and biomedical. In Vietnam, perovskite materials be of interest research and applications are strong but with major research direction is to go deep into the electrical properties and the magnetic properties. The Lanthanum Strontium manganite is a perovskite-based crystal-structured ceramic material with the formula of La1-xSrxMnO3, where x describes the doping ratio. It has attracted much attention due to its good magnetic, electrical, and catalytic properties and is becoming an attractive possibility material in several biomedical applications, particularly with nano-size. In industry, this material is commonly used in as a cathode material in commercially produced solid oxide fuel cells. In this thesis, we present the Perovskite nanoparticles La1-xSrxMnO3 were successfully synthesized of the nanosize La1-xSrxMnO3 at x = 0; 0.1; 0.2; 0.3 and 0.4 which prepared by a modified sol-gel method. Structure and magnetic properties of them were systematically investigated in dependence on doped Sr ratio x. The structure was investigated by XRD and show slightly changed but magnetic properties varied strongly with changing the doping ratio x. Magnetic properties of samples were studied by Vibrating Sample Mode of Physical Properties Measurement System show at the room temperature, the samples show superparamagnetic properties with high saturated magnetization MS of 57 emu/g which strongly dependents on the doped Sr ratio x.
Characterization of different dopants in TiO2 Structure by Pulsed Laser Dep...sarmad
Characterization of different dopants in TiO2 Structure by Pulsed Laser Deposition
A thesis submitted By: Khaled Z.Yahya
Supervised by: Prof.Dr. Adawiya J.Haider Prof.Dr. Raad M.S.Al-Haddad
Spectroscopic studies on Mn2+ ions doped Cadmium Aluminum Fluoro Lead Borate ...IJERA Editor
This article reports on optical properties of Mn2+ (0.5 mol%): 49.5 B2O3 - 10PbO - 30CdO -10AlF3 glasses.
Optical absorption spectrum of the manganese ions doped glass exhibits broad absorption band at 473 nm.
Photoluminescence spectrum of Mn2+ (0.5 mol %): 49.5B2O3- 30CdO – 10PbO - 10AlF3 glass has revealed a red
emission at 618 nm with an excitation wavelength 467 nm.
K2O - CdO - B2O3 – SiO2glasses containing different concentrations of MnO2 have been prepared. The Physical properties of the glasses are studied from their density. The studies have been analysed in the light of different oxidation states of manganese ion with the aid of the data from optical absorption. The analysis shows that manganese ions exist mainly in Mn2+ state, occupy tetrahedral positions and increase the insulating strength of the glass if MnO2 is present in smaller concentrations.
Infrared Spectral and EPR Studies of Mn2+ Ions Doped K2O - CdO - B2O3 - SiO2 ...inventionjournals
International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
Effect of Annealing on the Structural and Optical Properties of Nanostr...sarmad
Effect of Annealing on the Structural and Optical Properties of Nanostructured TiO2 Films Prepared By PLD. تأثير التلدين على الخواص التركيبية والبصرية لأغشية أوكسيد التيتانيوم (TiO2) ذات التراكيب النانوية المحضرة بتقنية ترسيب الليزر النبضي (PLD)
Preparation, Structure, and Characterization of Nd2mo2o9 fast Oxide Ion Condu...IJARIIT
The structure and ion conductivity of Nd2Mo2O9powders were synthesized by using Nd(NO2)3, MoO3, and aspartic acid (fuel) in assisted combustion method with heating at 550˚C for 6 hours. The thermal decomposition, phase identification, morphology, ionic conductivity of the samples were studied by TGA/DTA, XRD and SEM four probe D.C. method respectively. The formation of Nd2Mo2O9 was confirmed by FTIR studies. The synthesis and crystallization were followed by thermochemical techniques (TGA/DTA) studies. The synthesized materials showed reasonable ionic conductivity. These results indicate that assisted combustion method is a promising method to prepare nanocrystalline Nd2Mo2O9 for solid oxide fuel cell.
Synthesis Of Nanostructured TiO2 Thin Films By Pulsed Laser Deposition (PLD) ...sarmad
Sarmad Sabih Al-Obaidi
Ali Ahmed Yousif
Abstract
In this work, nanostructured TiO2 thin films were grown by pulsed laser deposition (PLD) technique on glass substrates. TiO2 thin films then were annealed at 400-600 °C in air for a period of 2 hours. Effect of annealing on the structural and morphological were studied. Many growth parameters have been considered to specify the optimum conditions, namely substrate temperature (300 °C), oxygen pressure (10-2 Torr), laser fluence energy density (0.4 J/cm2), using double frequency Q-switching Nd:YAG laser beam (wavelength 532nm), repetition rate (1-6 Hz) and the pulse duration of 10 ns. The results of the X-ray test show that all nanostructures tetragonal are polycrystalline. These results show that grain size increase from 19.5 nm to 29.5 with the increase of annealing temperature. The XRD results also reveal that the deposited thin film, annealed at 400 °C of TiO2 have anatase phase. Thin films annealed at 500 °C and 600 °C have mixed anatase and rutile phases. Full Width at Half Maximum (FWHM) values of the (101) peaks of these films decrease from 0.450° to 0.301° with the increase of annealing temperature. Surface morphology of the thin films have been studied by using atomic force microscopes (AFM). AFM measurements confirmed that the films have good crystalline and homogeneous surface. The Root Mean Square (RMS) value of thin films surface roughness are increased with the increase of annealing temperature.
الخلاصة
على (PLD) النانویة بوساطة تقنیة ترسیب اللیزر النبضي (TiO في ھذا البحث، تم انماء أغشیة اوكسید التیتانیوم ( 2
الرقیقة من 400 الى 600 درجة مئویة في الھواء مدة ساعتین . ودرس تأثیر TiO قواعد زجاجیة. ومن ثم لدنت أغشیة 2
التلدین في الخصائص التركیبیة والطبوغرافیة. عوامل عدیدة لأنماء الأغشیة اخذت بنظر الاعتبار لتحدید الحالة المثلى مثل
0.4 ) باستخدام J/cm 10-2 ) ،كثافة طاقة الفیض اللیزري( 2 Torr) 300 ) ،ضغط الأوكسجین ºC) درجة حرارة القاعدة
532 بمعدل تكراریة - 1 nm التردد المضاعف للیزر النیدیمیوم- یاك الذي یعمل بتقنیة عامل النوعیة عند الطول الموجي
6 ھرتز) وامد نبضة 10 نانوثانیة. تظُھر نتائج فحوصات الأشعة السینیة أن جمیع التراكیب النانویة رباعیة متعددة )
التبلور. وان ھذه النتائج تظھر زیادة في حجم الحبیبات من 19.5 نانومتر الى 29.5 نانومترمع زیادة درجة حرارة التلدین.
نتائج الأشعة السینیة اظھرت ایضا ان الغشاء المرسب والملدن في 400 درجة مئویة لثنائي اوكسید
Synthesis and charaterization of la1 x srxmno3 perovskite nanoparticlesMai Trần
In recent times perovskite materials are extensively studied and have attracted much attention because they exhibit interesting the properties, showing potential applications in commercial, technical and biomedical. In Vietnam, perovskite materials be of interest research and applications are strong but with major research direction is to go deep into the electrical properties and the magnetic properties. The Lanthanum Strontium manganite is a perovskite-based crystal-structured ceramic material with the formula of La1-xSrxMnO3, where x describes the doping ratio. It has attracted much attention due to its good magnetic, electrical, and catalytic properties and is becoming an attractive possibility material in several biomedical applications, particularly with nano-size. In industry, this material is commonly used in as a cathode material in commercially produced solid oxide fuel cells. In this thesis, we present the Perovskite nanoparticles La1-xSrxMnO3 were successfully synthesized of the nanosize La1-xSrxMnO3 at x = 0; 0.1; 0.2; 0.3 and 0.4 which prepared by a modified sol-gel method. Structure and magnetic properties of them were systematically investigated in dependence on doped Sr ratio x. The structure was investigated by XRD and show slightly changed but magnetic properties varied strongly with changing the doping ratio x. Magnetic properties of samples were studied by Vibrating Sample Mode of Physical Properties Measurement System show at the room temperature, the samples show superparamagnetic properties with high saturated magnetization MS of 57 emu/g which strongly dependents on the doped Sr ratio x.
Characterization of different dopants in TiO2 Structure by Pulsed Laser Dep...sarmad
Characterization of different dopants in TiO2 Structure by Pulsed Laser Deposition
A thesis submitted By: Khaled Z.Yahya
Supervised by: Prof.Dr. Adawiya J.Haider Prof.Dr. Raad M.S.Al-Haddad
Spectroscopic studies on Mn2+ ions doped Cadmium Aluminum Fluoro Lead Borate ...IJERA Editor
This article reports on optical properties of Mn2+ (0.5 mol%): 49.5 B2O3 - 10PbO - 30CdO -10AlF3 glasses.
Optical absorption spectrum of the manganese ions doped glass exhibits broad absorption band at 473 nm.
Photoluminescence spectrum of Mn2+ (0.5 mol %): 49.5B2O3- 30CdO – 10PbO - 10AlF3 glass has revealed a red
emission at 618 nm with an excitation wavelength 467 nm.
K2O - CdO - B2O3 – SiO2glasses containing different concentrations of MnO2 have been prepared. The Physical properties of the glasses are studied from their density. The studies have been analysed in the light of different oxidation states of manganese ion with the aid of the data from optical absorption. The analysis shows that manganese ions exist mainly in Mn2+ state, occupy tetrahedral positions and increase the insulating strength of the glass if MnO2 is present in smaller concentrations.
Infrared Spectral and EPR Studies of Mn2+ Ions Doped K2O - CdO - B2O3 - SiO2 ...inventionjournals
International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
Effect of Annealing on the Structural and Optical Properties of Nanostr...sarmad
Effect of Annealing on the Structural and Optical Properties of Nanostructured TiO2 Films Prepared By PLD. تأثير التلدين على الخواص التركيبية والبصرية لأغشية أوكسيد التيتانيوم (TiO2) ذات التراكيب النانوية المحضرة بتقنية ترسيب الليزر النبضي (PLD)
Removal of lead ions by nife2 o4 nanoparticleseSAT Journals
Abstract Nickel ferrite nanoparticles have been prepared by polymeric precursor method. The nanoparticles application in the removal of lead ion was investigated. The results showed that the adsorptive properties were dependent on pH, duration and temperature. Highest percentage (99%) lead adsorption was observed under basic condition at room temperature during 1 h stirring. Analysis of lead adsorbed nickel ferrite by powder XRD, FTIR and XPS techniques revealed the adsorption took place based on hydroxide mechanism. The lead salt formed on the surface of the ferrite powder was identified to be lead carbonate and lead hydroxy carbonate at pH 7 and 9 respectively. Keywords: Nickel ferrite; Nanoparticles; Lead; Adsorption; Hydroxide
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Spectroscopic properties of lithium borate glass containing Sm3+ and Nd3+ ionsIJAAS Team
Lithium borate glass samples mixed with a different concentration of Sm3+ and Nd3+ ions organized by quenching technique. Structural, vibration groups and spectral properties of glass samples investigated using X-ray diffraction, FTIR, UV/Vis/NIR and photoluminescence spectroscopy. The X-ray confirmed the lithium borate glass samples containing Sm3+ and Nd3+ ions in the amorphous state. Luminescence spectra of glass samples excited at 400 nm recorded, here three luminescence bands observed in Visible region, which due to spectra materials (Sm3+, Nd3+). These indicate that these glass samples responsible orange emission and used in the improvement of materials for LED, and optical devices. The functional vibration groups of the glass matrix studied using FTIR spectroscopy.
Synthesis, characterization and electrocatalytic activity of silver nanorods ...kutty79
This paper describes a simple method of synthesizing silver nanorods using the polyol process, where propylene glycol serves both as a reducing
agent and as a solvent in the presence of a capping reagent such as polyvinylpyrrolidone (PVP). The diameter and length of silver nanorods could be
controlled by changing the AgNO3/PVP ratio. The end-to-end assembly of the silver nanorods was found. The silver nanorods were characterized by
using scanning electron microscopy, transmission electron microscopy, X-ray diffraction and absorption spectroscopy. The catalytic activity of a
glassy carbon electrode with Ag nanorods exhibits extraordinary electrocatalytic activities towards the electro-reduction of benzyl chloride.
This article reports on the optical analysis of Cu2+ (0.5 mol %): 59.5B2O3 – 20 TeO2 – 10CdO – 10Li2O glass.
From XRD spectrum , amorphous nature of the glass has been studied. Absorption spectrum of the copper glass
shows a broad absorption band (2B1g→2B1g) at 829 nm has been observed. Emission spectrum of Cu2+ (0.5 mol
%): 59.5B2O3 – 20 TeO2 – 10CdO – 10Li2O glass has exhibits a blue emission at 439 nm with an excitation
wavelength 379 nm.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Study of Annealing Effect on the Some Physical Properties of Nanostructured T...sarmad
Ali A.Yousif ● , Sarmad S. Al-Obaidi ●●
Abstract
Nanostructured Titanium Dioxide (TiO2) thin films were prepared by pulsed
laser deposition (PLD) on the glass substrates. The effects of different annealing
temperature (400, 500 and 600 °C) towards the some physical properties such as
structural, morphological and optical have been studied. From X-ray diffraction
result, the crystallinity of TiO2 thin films improved at higher annealing
temperature. It also could be observed that the rutile phase start to exist at
annealing temperatures of 500 °C and 600 °C. The Full Width at Half
Maximum (FWHM) of the (101) peaks of these films decreases from 0.450° to
0.301° with increasing of annealing temperature. AFM measurements confirmed
that the films grown by this technique have good crystalline and homogeneous
surface. The Root Mean Square (RMS) value of thin films surface roughness
increased with increasing of the annealing temperature. From UV-VIS
spectrophotometer measurements, the optical transmission results shows that the transmission over than ~65% in the near-infrared region which decrease with the increasing of annealing temperatures. The allowed indirect optical band gap of the films was estimated to be in the range from 3.49 to 3.1 eV. The allowed direct band gap was found to decrease from 3.74 eV to 3.55 eV with the increase of annealing temperature. The refractive index of the films was found from 2.27 -2.98 at 550nm. The extinction coefficient, real and imaginary parts of the dielectric constant increase with annealing temperature.
Development of Ni-doped Yttria stabilized Zirconia composite for SOFC applica...IOSRJAP
Ni-doped Yttria stabilized Zirconia (NiO/YSZ) has been synthesized using low cost combustion process from an aqueous solution containing ZrO(NO3)2.6H2O, Y(NO3)3.6H2O, Ni(NO3)2.6H2O and urea. Pellets were sintered at 13500C for 5 hours and its sintered density is estimated to be of 95%. Sintered pellets were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM) & X-ray photoelectron spectroscopy (XPS) techniques. From the XRD analysis, as grown powder of NiO/YSZ showed nano-crystalline behavior with homogeneous mixture of YSZ and NiO phases. However sintered powder showed µ-size dense grain growth. Temperature and frequency dependent dielectric properties are corroborated with the conduction mechanism. Both dielectric constant (K) and loss (tan δ) are increased sharply at high temperature region, which is expected to be the onset of dipolar relaxation phenomena due to the presence of oxygen vacancies. A mixed conductivity involving ionic conduction in the high temperature range and electronic conduction in the low temperature range was observed. The decrease in K and tan δ with increase in frequency at a given temperature suggests the dynamic interaction of oxygen vacancies & oxide ion pairs.
Removal of lead ions by nife2 o4 nanoparticleseSAT Journals
Abstract Nickel ferrite nanoparticles have been prepared by polymeric precursor method. The nanoparticles application in the removal of lead ion was investigated. The results showed that the adsorptive properties were dependent on pH, duration and temperature. Highest percentage (99%) lead adsorption was observed under basic condition at room temperature during 1 h stirring. Analysis of lead adsorbed nickel ferrite by powder XRD, FTIR and XPS techniques revealed the adsorption took place based on hydroxide mechanism. The lead salt formed on the surface of the ferrite powder was identified to be lead carbonate and lead hydroxy carbonate at pH 7 and 9 respectively. Keywords: Nickel ferrite; Nanoparticles; Lead; Adsorption; Hydroxide
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Spectroscopic properties of lithium borate glass containing Sm3+ and Nd3+ ionsIJAAS Team
Lithium borate glass samples mixed with a different concentration of Sm3+ and Nd3+ ions organized by quenching technique. Structural, vibration groups and spectral properties of glass samples investigated using X-ray diffraction, FTIR, UV/Vis/NIR and photoluminescence spectroscopy. The X-ray confirmed the lithium borate glass samples containing Sm3+ and Nd3+ ions in the amorphous state. Luminescence spectra of glass samples excited at 400 nm recorded, here three luminescence bands observed in Visible region, which due to spectra materials (Sm3+, Nd3+). These indicate that these glass samples responsible orange emission and used in the improvement of materials for LED, and optical devices. The functional vibration groups of the glass matrix studied using FTIR spectroscopy.
Synthesis, characterization and electrocatalytic activity of silver nanorods ...kutty79
This paper describes a simple method of synthesizing silver nanorods using the polyol process, where propylene glycol serves both as a reducing
agent and as a solvent in the presence of a capping reagent such as polyvinylpyrrolidone (PVP). The diameter and length of silver nanorods could be
controlled by changing the AgNO3/PVP ratio. The end-to-end assembly of the silver nanorods was found. The silver nanorods were characterized by
using scanning electron microscopy, transmission electron microscopy, X-ray diffraction and absorption spectroscopy. The catalytic activity of a
glassy carbon electrode with Ag nanorods exhibits extraordinary electrocatalytic activities towards the electro-reduction of benzyl chloride.
This article reports on the optical analysis of Cu2+ (0.5 mol %): 59.5B2O3 – 20 TeO2 – 10CdO – 10Li2O glass.
From XRD spectrum , amorphous nature of the glass has been studied. Absorption spectrum of the copper glass
shows a broad absorption band (2B1g→2B1g) at 829 nm has been observed. Emission spectrum of Cu2+ (0.5 mol
%): 59.5B2O3 – 20 TeO2 – 10CdO – 10Li2O glass has exhibits a blue emission at 439 nm with an excitation
wavelength 379 nm.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Study of Annealing Effect on the Some Physical Properties of Nanostructured T...sarmad
Ali A.Yousif ● , Sarmad S. Al-Obaidi ●●
Abstract
Nanostructured Titanium Dioxide (TiO2) thin films were prepared by pulsed
laser deposition (PLD) on the glass substrates. The effects of different annealing
temperature (400, 500 and 600 °C) towards the some physical properties such as
structural, morphological and optical have been studied. From X-ray diffraction
result, the crystallinity of TiO2 thin films improved at higher annealing
temperature. It also could be observed that the rutile phase start to exist at
annealing temperatures of 500 °C and 600 °C. The Full Width at Half
Maximum (FWHM) of the (101) peaks of these films decreases from 0.450° to
0.301° with increasing of annealing temperature. AFM measurements confirmed
that the films grown by this technique have good crystalline and homogeneous
surface. The Root Mean Square (RMS) value of thin films surface roughness
increased with increasing of the annealing temperature. From UV-VIS
spectrophotometer measurements, the optical transmission results shows that the transmission over than ~65% in the near-infrared region which decrease with the increasing of annealing temperatures. The allowed indirect optical band gap of the films was estimated to be in the range from 3.49 to 3.1 eV. The allowed direct band gap was found to decrease from 3.74 eV to 3.55 eV with the increase of annealing temperature. The refractive index of the films was found from 2.27 -2.98 at 550nm. The extinction coefficient, real and imaginary parts of the dielectric constant increase with annealing temperature.
Development of Ni-doped Yttria stabilized Zirconia composite for SOFC applica...IOSRJAP
Ni-doped Yttria stabilized Zirconia (NiO/YSZ) has been synthesized using low cost combustion process from an aqueous solution containing ZrO(NO3)2.6H2O, Y(NO3)3.6H2O, Ni(NO3)2.6H2O and urea. Pellets were sintered at 13500C for 5 hours and its sintered density is estimated to be of 95%. Sintered pellets were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM) & X-ray photoelectron spectroscopy (XPS) techniques. From the XRD analysis, as grown powder of NiO/YSZ showed nano-crystalline behavior with homogeneous mixture of YSZ and NiO phases. However sintered powder showed µ-size dense grain growth. Temperature and frequency dependent dielectric properties are corroborated with the conduction mechanism. Both dielectric constant (K) and loss (tan δ) are increased sharply at high temperature region, which is expected to be the onset of dipolar relaxation phenomena due to the presence of oxygen vacancies. A mixed conductivity involving ionic conduction in the high temperature range and electronic conduction in the low temperature range was observed. The decrease in K and tan δ with increase in frequency at a given temperature suggests the dynamic interaction of oxygen vacancies & oxide ion pairs.
En esta presentación es una recopilación breve de los conceptos, variables, factores, objetivos, estrategias,análisis, tactica y control:PROMOCIÓN. Y Definición de MERCADO. El papel de la promoción en la mezcla de mercadeo. Así como en el
proceso de comunicación y promoción y ell lugar de la promoción en la organización.
Importancia de la promoción para la empresa y los mercados.
Por otro lado . El presupuesto de promoción.
Organismos y leyes que impactan en la mezcla promocional: Indepabis.Ley de Defensa de las Personas en el Acceso a los Bienes y Servicios
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Application of Fe3O4 Sphere Doped with Zn for Enhanced Sonocatalytic Removal ...ijtsrd
Fe3O4 sphere doped Zn were successfully prepared by the simple one pot solvothermal method. Morphology and structure of the as synthesised products was checked through the XRD, SEM, HRTEM techniques. The Fe3¬O4 hollowsphere doped showed the high photocatalytic activity for degradation of hexavalent chromium under visible light irradiation. The effects of reaction conditions such as initial pH, photocatalyst dosage and hexavalent chromium contratentation were also studied systematically. The stability of the catalsyts and and possible catalytic mechanism was also proposed. The results indicate that Fe3O4 sphere doped Zn can be promising catalyst for photo reduction of hexavalent chromium. Xuan Sang Nguyen "Application of Fe3O4 Sphere Doped with Zn for Enhanced Sonocatalytic Removal of Cr (VI) From Aqueous Solutions" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-6 | Issue-1 , December 2021, URL: https://www.ijtsrd.com/papers/ijtsrd47862.pdf Paper URL: https://www.ijtsrd.com/medicine/other/47862/application-of-fe3o4-sphere-doped-with-zn-for-enhanced-sonocatalytic-removal-of-cr-vi-from-aqueous-solutions/xuan-sang-nguyen
Spectroscopic and Physical Properties of Mn2+ spin probe in RO-P2O5-ZnO-Pb3O4...IJERA Editor
RO-P2O5-ZnO-Pb3O4 (R=Li, Na and K) glasses containing 0.1concentrations of MnO have been prepared. The structural, optical and physical properties of prepared glasses are studied by XRD, UV-Visible, EPR and FTIR techniques. The nature of local symmetry and structural information of the neighboring atoms of dopant ions (Mn2+) in the host matrix have been understood by evaluating the crystal field strength (Dq) and Racah (B & C) parameters. The combined analysis of optical absorption and EPR spectroscopy has indicated that the manganese ions exist in Mn2+ (in octahedral) local coordination sites. FTIR results showed that PO4 are the main structural unit of the glass system and the manganese ions are located in the glass matrix network.
Electrochemical Synthesis of MoO3 Nanoparticles Effect of Temperature Convert...IJERA Editor
MoO3 nanorods were prepared by electrochemical reduction method using the tetra propyl ammonium bromide (TPAB) was structure directing agent in an organic medium viz. tetra hydro furan (THF) and acetonitrile (ACN) in 4:1 ratio and at current density 14mA &18 mA. The reduction process takes place under atmospheric condition over a period of 2 h. Dried sample was calcinated in muffle furnace at 500ºC. The parameters such as current density and concentration of stabilizers were used to control the size of nanorods. The synthesized MoO3 nanorods were characterized by using UV-Visible, FT-IR, XRD, SEM-EDS and TEM analysis techniques.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Studies of the Atomic and Crystalline Characteristics of Ceramic Oxide Nano P...Mahendra Kumar Trivedi
In the present study, some transition metal oxides (Zinc oxide, iron oxide and copper oxide) which are widely used in the fabrication of electronic devices were selected and subjected to biofield treatment.
Effect of Sn Doping on Structural and Electrical Properties of ZnO Thin Films...journal ijrtem
Abstract: Un-doped and tin (Sn) doped ZnO films were deposited on heated glass substrates by chemical spray pyrolysis method
(CSP). The effect of Sn concentration on the structural, surface morphological and electrical properties of the SnO2 films was
investigated. XRD analyses showed that the obtained films are polycrystalline in nature with hexagonal structure with preferred
orientation of (101). Doping with tin (Sn) causes increase in the grain size. Atomic force microscopy images showed that the root
mean square of the average surface roughness's varied from (1.48 to 3.58) as dopant concentration increased from 0 to 5 wt.%. The
electrical properties of the Sn ZnO films were strongly influenced by doping concentration. The electrical resistance of the films was
sharply decreased as dopant concentration increased.
Keywords: (ZnO) thin films, Sn Doping, Structural and electrical Properties
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
Structure, microstructure and dielectric study of (ba0.6 sr0.4)(zr0.6ti0.4)o3...eSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
Structure, microstructure and dielectric study of (ba0.6 sr0.4)(zr0.6ti0.4)o3...
10.1007_s11082-014-9975-2
1. 1 23
Optical and Quantum Electronics
ISSN 0306-8919
Opt Quant Electron
DOI 10.1007/s11082-014-9975-2
Effect of heating rate on structural and
optical properties of Si and Mg co-doped $$
hbox {ZrO}_{2}$$ ZrO 2 nanopowders
Nasrollah Najibi-Ilkhechi, Behzad
Koozegar-Kaleji & Esmaiel Salahi
2. 1 23
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4. N. N. Ilkhechi et al.
melting point (3,253◦C), it is cubic (C-ZrO2) (Morava and Smolik 2007; Castro and Reyes
2002). When zirconia nanopowders is prepared via the sol–gel method, the tetragonal phase
can be stabilized at low temperatures, depending on pH and the hydrolysis catalysts used
in the synthesis (Gomez et al. 1998). The stabilization of doped zirconia by metals in the
tetragonal and cubic phases has been earlier reported. Stabilizers such as Y2O3, MgO, CaO,
Cr2O3, Fe2O3, NiO, and CuO are commonly doped into zirconia nanopowders to promote
the retention of the high temperature polymorphs. The main aim of using these metal oxides
as dopants is to obtain zirconia in the cubic and tetragonal phases with a high BET surface.
Also, increasing the content of stabilizers favors meta-stabilization of both tetragonal and
cubic polymorphs (Ramaswamy and Bhagwat 2004; Chraska and King 2000; Bhagwata and
Ramaswamy 2003; Karagedov and Shatskaya 2006; Adamski et al. 2007; Qu and Chu 2007;
Suciu et al. 2007).
Septawendar et al. (2013) reported that the nanoparticles of calcia-stabilized zirconia
consisted of the cubic and the tetragonal phases of zirconia after calcination at 500◦C. It has
been proved that using 25% ammonia solution as a catalyst stabilizes the tetragonal phase
of zirconia (Ca-SZA, calcia-stabilized zirconia) at 500–700◦C.
Aguilar et al. (2000) showed that polymorphic tetragonal-monoclinic transformation
region was observed in zirconia-rich compositions, meaning that the critical size of the
tetragonal-monoclinic transformation decreased as SiO2 content increased.
Tan et al. (2011) proposed synthesized pure cubic zirconia nanocrystallites by a simple
method of femtosecond-pulsed laser ablation in ammonia at different pulse powers, while a
mixture of tetragonal and monoclinic zirconia was obtained in water. Jayakumar et al. (2013)
Showed that monoclinic phase is found to be stable when particle size is bigger than 20nm,
tetragonal is found to be stabilized in the range of 7–20nm and the cubic phase is stabilized
as the particle size decreases to 6nm and less.
The optical properties (French et al. 1994) and especially the photoluminescence (PL)
properties of ZrO2 have been seldom reported, although PL has already been observed in a
ZrO2 sol and nanoparticle systems (Emeline et al. 1998). Ionic sizes of dopants also influence
crystallite sizes in doped ZrO2 samples. Small crystallite sizes of ZrO2 are usually obtained
when the ionic sizes of dopants are largely different from Zr4+ (Hartridge et al. 2001). The
electronic structures of ZrO2 are also altered by dopants because of introduced energy levels
(Kralik et al. 1998). ZrO2 is a direct band gap insulator with two direct band to band transitions
respectively at 5.2 and 5.79eV. The experimental values for ZrO2 (tetragonal)band gap in
the range of 5.8–6.6eV, according to the results reported by Emeline and Serpon (2001).
The dependence of the absorption coefficient (α) on the photon energy (hυ) in the band-edge
spectral region for a direct transition is shown by a relation: αhυ = Const (hυ − Eg)1/2,
where Eg is the band gap of the solid (Pankove 1971). The electronic structures of ZrO2
are also altered by dopants because of introduced energy levels (Kralik et al. 1998). UV–Vis
spectra for various zirconia nanostructures show a sharp absorption peak centered at about
290nm.
The wide band gap has been reduced to 2.3 and 2.8eV, respectively, when 5wt.% of Fe3+
or V5+ is doped (Saadoune et al. 2003).
In this paper, ZrO2 nanopowders, doped by Si+4 and Mg+2, were prepared by sol–gel
method. The aim of the present work was to investigate the effect of cations presence at
different heating rate on the band gap energy of zirconia crystals by studying its XRD and
optical property.
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5. Effect of heating rate on structural and optical properties of Si and Mg
2 Experimental procedures
2.1 Preparation of doped zirconia nanoparticles
The preparation of precursor solution for Si and Mg doped ZrO2 nanopowders was as fol-
lows: ZrO2, MgO and SiO2 sols were prepared, separately. For the preparation of ZrO2 sol,
ZrO(NO3) · H2O (Loba chemie) was used as precursor. 2ml Zirconyl Nitrate was added to
20ml ethanol then stirred well to synthesize pure ZrO2 sol. Ethanol was used as a media for
uniformly polymerization. After adding 3ml nitric acid (HNO3) to as catalyst to the solu-
tion, 5ml De-ionized water was added to the solution slowly to initiate hydrolysis process.
Solution was aged for 24h in order to complete all reactions.
ThechemicalcompositionoftheresultantsolutionwasZirconylNitrate:H2O: HNO3:Ethyl
aceto acetate (EAcAc):ethanol (EtOH)=1:2.5:1.5:2:10 in volume ratio. In order to prepare
MgO sol and SiO2 sol, tetraethoxysilane (Si(OC2H5)4, Aldrich) were dissolved in ethanol
with volume ratio of TEOS:ethanol = 1:8 and MgCl2:ethanol = 1:10 at ambient tempera-
ture with continuous stirring. For the co-doping ZrO2, Si doping was made for 10min after
Mg doping under continuous stirring at room temperature. Subsequently, the formed gel
was dried at 100◦C. The prepared samples were calcined at 800◦C for different heating
rate.
2.2 Characterization methods
XRD patterns and phase identification of the samples were recorded using X-ray diffraction
analysis (Philips, MPD-XPERT, λ:Cu Kα = 0.154nm). The samples were scanned in the 2θ
range of 20–70◦. The average crystallite size of nanopowders (d) was determined from the
XRD patterns, according to the Deby-Scherrer Eq. (1) (Wang et al. 2007)
D =
kλ
β cos θ
(1)
where k is a constant (shape factor, about 0.9), λ the X-ray wavelength (0.154nm), β the full
width at half maximum (FWHM) of the diffraction peak, and θ is the diffraction angle. The
values of β and θ of Tetragonal and Cubic phases were taken from Tetragonal (1 0 1) and
Cubic (1 1 1) planes diffraction lines, respectively.
Microstructural characteristics such as particle size and morphology of synthesized pow-
ders were analyzed by high resolution transmission electron microscopy (TEM) (Philips
CM200) at the accelerating voltage of 100 kV.
2.3 Band gap energy measurement
The proper amounts of dispersant (HNO3) was added to 50ml distilled water, followed
by the addition of 0.01g of samples calcined at different heating rates for Z-20%Si, Z-
20%Mg and Z-20%Si-20%Mg. The pH of suspension was adjusted to a desired value and
the suspension was stirred for 30 min using a magnetic stirrer and subjected to a subse-
quent treatment in an ultrasonic bath for 60 min. The specimens were stirred again for 30
min using a magnetic stirrer. The dispersion stability of doped ZrO2 aqueous suspension
was evaluated by the absorbance of suspension using a mini1240 Shimadzu UV–visible
spectrometer.
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6. N. N. Ilkhechi et al.
3 Results and discussion
3.1 X-ray diffraction studies of pure and doped zirconia nanopowders
XRD patterns of the doped ZrO2 nanopowders calcined at 800◦C for 2h with different heating
rates is shown in Fig. 1. Patterns show the effect of heating rate and doping on the phase
structures of ZrO2 nanopowders. All samples were identified as the mixture polymorphs
of tetragonal (JCPDS: No.050-1089), cubic (JCPDS: No.49-1642), and monoclinic phases
(JCPDS: No.80-0966). X-ray diffraction peaks at 2θ = 30.12◦, 30.27◦ and 28.1◦ are indexed
as (0 1 1), (1 1 1) and (−1 1 1) planes of tetragonal, cubic, and monoclinic phases, respectively.
In Fig. 1a, the XRD of 20%Si doped ZrO2 at different heating rate are shown.
Fig. 1 XRD pattern of a 20%Si doped ZrO2 b 20%Mg doped ZrO2 c 20%Si and 20%Mg co-doped ZrO2
at different heating rate. a 1◦C/min, b 4◦C/min, c 7◦C/min d 10◦C/min
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7. Effect of heating rate on structural and optical properties of Si and Mg
Table 1 Characteristic of doped ZrO2 at different heating rates (d: crystallite size (nm))
Sample code 1 ◦C/min 4 ◦C/min 7 ◦C/min 10 ◦C/min
dT dM dC dT dM dC dT dM dC dT dM dC
Z-20%Si 13 — 21 12 — 27 62 26 35 — — 20
Z-20%Mg — — — 29 28 24 72 23 47 27 12 22
Z-20%Si-20%Mg 29 — 48 49 — 34 37 — 21 23 — 18
As heating rate increased, broad peaks were detected at lower heating rates became sharper
which shows the evolution of a crystalline phase up to heating rate of 7◦C/min and then
decreased. At higher heating rate (10◦C/min), the cubic zirconia was dominant and the major
phase. After annealin nanocrystalline non doped zirconia, the tetragonal phase transformed
to the monoclinic phase, a transformation that begins at approximately 450◦C and can be
completed between 800 and 1,000◦C. In the Si doped ZrO2, however, the formation of
Z(T) was detected via XRD pattern as the beginning in the thermal treatment at 800◦C and
remained up to heating rate of 7◦C/min. The presence of Z(T) and Z(M) was confirmed
by recording the XRD pattern at heating rates of 1–7◦C/min which is due to the modified
Zirconia crystallization behavior by addition of silicon oxide.
In the sample with the 20%Mg doped ZrO2 (Fig. 1b), the solubility limit for MgO in
zirconia increased and formed as cubic MgO (P) at 4–10◦C/min. The monoclinic phase
was formed at other heating rates. In Z-20%Mg sample (Fig. 1b), XRD showed a nearly
amorphous pattern, with traces of Monoclinic zirconia, indicated by a peak at 31.5◦. At
higher heating rate (7◦C/min), a substantial increase in intensity of the three phases was
observed. Results showed that the effect of Mg dopant on stability of monoclinic phase was
higher than Si.
The Z-20%Si-20%Mg (Fig. 1c) showed no periclase phase (MgO), and tetragonal and
cubic phase were deteced at all heating rates comparing to other samples (Fig. 1a, b). This
can prove that adding Si and Mg dopants inhibited the formation of cubic MgO and decreased
the intensity of monoclinic phase. Calcination of samples at higher heating rate (10◦C/min)
eliminated monoclinic phase and decreased the intensity of tetragonal and cubic phases. the
amorphous silica inhibited the formation of monoclinic and periclase phases at high heating
rates. Table 1 shows that the dependence of depending crystallite size with the heating rate.
3.2 UV–vis absorption
UV–Vis spectra were acquired in the wavelength region of 300–800nm for all samples Fig. 2
shows the UV–visible absorption spectra of doped ZrO2 nanoparticles annealed at different
heating rates. All the samples exhibit an absorption peak around 400–500nm.
To estimate the value of the direct band gap of doped ZrO2 nanoparticles from the absorp-
tion spectra, the Tauc relation was used (Manoj and Beena 2011).
(α h υ)1/n
= A(h υ −Eg) (2)
where A is a constant, Eg is the band gap of the material, α is the absorption coefficient and
the exponent ‘n’ depends on the type of transition (n =1/2 and 2 for direct and indirect band
gap semiconductors), hν is the photon energy, respectively. The best linear relationship was
obtained by plotting (αh ν)2 against photon energy (hν), indicating that the absorption edge
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8. N. N. Ilkhechi et al.
Fig. 2 UV–Vis absorption spectra of the a 20%Si b 20%Mg c 20%Si and 20%Mg doped ZrO2 nanopowders
at different heating rate
Table 2 Band gap (eV) of doped ZrO2 at different heating rates
Sample code 1 (◦C/min) 4 (◦C/min) 7 (◦C/min) 10 (◦C/min)
Z-20%Si 3.8 3.9 3.1 4
Z-20%Mg 4.1 4 3 3.2
Z-20%Si-20%Mg 3.9 3.7 3.7 3.8
was due to a direct allowed transition. The line fit to the (αh ν)2 versus hν plot is obtained
by fitting a straight line to the linear portion of the curve. The value of optical band gap were
determined from the value of intercept of the straight line at α = 0. The values of band gap of
Si doped ZrO2 (Fig. 2a) calculated from Tauc plots were found to be 3.8, 3.9, 3.1 and 4eV for
the heating rates of 1, 4, 7, and 10◦C/min, respectively. It is clear from Tables 1 and 2 that the
band gap decreases with the increase in heating rate, while the crystallite size of tetragonal
and cubic phase increases. It has been observed that the band gap was maximum (4eV) when
the average crystallite was (20nm) at 10◦C/min and while it was minimum (3.1eV) with
average crystallite size of 41nm at 7◦C/min.
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9. Effect of heating rate on structural and optical properties of Si and Mg
Fig. 3 SEM images of doped ZrO2. a Z-20%Si, b Z-20%Mg, c Z-20%Si-20%Mg at heating rate 7◦C/min
Theabsorptionspectraof20%MgdopedZrO2 nanoparticlesisshownFig.2b.Weobtained
the maximum band gap to be 4.1eV at heating rate of 1◦C/min. The decreasing trend hap-
pened at heating rates od 4, 7, and 10◦C/min for 20%Mg doped ZrO2 samples as 4, 3 and
3.2eV, respectively. Average crystallite for minimum band gap was (47nm) at 7◦C/min.
The band gap of the 20%Mg and 20%Si co-doped ZrO2 nanoparticles is calculated to
be 3.7–3.9eV from the UV–Visible absorption spectrum (Fig. 2c). Light absorption leads
to formation of electron in the conduction band and a positive hole in the valence band. In
small particles they are confined to potential wells of small lateral dimension and the energy
difference between the position of the conduction band and a free electron, which leads to a
quantization of their energy levels (Manoj and Beena 2011).
3.3 SEM and TEM analysis of the doped ZrO2 nanopowders
The surface morphological study of the doped ZrO2 nanoparticles was carried out using SEM
micrograph. Figure 3 shows the SEM image of the doped ZrO2 nanoparticles with heating
rate of 7◦C/min. It can be seen that the size of the co doped ZrO2 is smaller than Si or Mg
doped. Figure 3 indicates that SEM micrographs are consistent with the XRD results.
The particle morphologies of doped ZrO2 were observed by TEM, and the micrographs
are shown in Fig. 4. The Si/Mg co-doped particles are more dispersed than doped ZrO2
with particle sizes of 5–25nm (Fig. 4c). The Si/Mg doped ZrO2 nano-crystalline powders
prepared in non-aqueous system contained less hydroxyl groups than those synthesized in
aqueous system which causes less aggregation among nanocrystallites.
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10. N. N. Ilkhechi et al.
Fig. 4 TEM images of doped ZrO2 a Z-20%Si, b Z-20%Mg, c Z-20%Si-20%Mg at heating rate 7◦C/min
4 Conclusions
Si and Mg co-doped ZrO2 nanoparticles were successfully synthesized using sol–gel method.
The XRD patterns confirm the formation of tetragonal, cubic, and monoclinic phases of ZrO2
nanoparticles. No impurity phase was observed in XRD patterns of co-doped or Si doped. In
Mg doped sample, a small amount of impurity phase corresponding to MgO (periclase) was
observed. The optical studies confirmed that the band gap of the doped samples decreases
initially up to 7◦C/min after which it started to increase at heating rate of 10◦C/min. The
Mg doping in ZrO2 improves the optical properties of the ZrO2 nanoparticles.
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