"Current trends in research in physics and industrial applications" at Morbi

1. Current Trends in Research in Physics & Industrial Applications
Abstract Introducti
The manganite compounds Nd0.7Sr0.3MnO3 (NSMO) were prepared by Citrate Nitrate route in  “CMR”- The magnetoresistance is the dependence of the resistivity of a material
ordered to obtain high purity homogeneous powder and to lower the temperature values on the magnetic field, the MR was found to be extremely large. 1993, materials
on
Study of Nanostructured Perovskite Oxide of heat treatments. These compounds crystallized in an orthorhombic structure (Space
group pnma-62). In this route synthesis of NSMO based on the dissolution and
were found that could increase or decrease resistance not by a few percent but
order of magnitude. The term “colossal magnetoresistance”.
Nd0.7Sr0.3MnO3 (NSMO) Using CN-Gel Method homogenization of metal salts in citric acid-nitric acid mixture without using any
complexing aid. The mixture was heated in water bath at 80°C until got a golden brown
 The general formula of CMR manganite is RE1-xAxMnO3 (ABO3)(RE=rare earth like
colored transparent gel. The gel was further heated above 400°C for few hours and
Pooja A. Chhelavda, Jessica R. Chocha, Tejas M. Tank and J. A. resulted a foamy precursor which was decomposed and got black color flakes of extremely La, Nd, Pr etc., A = Ca, Sr, Ba and Pb). The most fundamental property of
fine particle size. The powder obtained by pulverized these flakes was divided into six these
Bhalodia parts and sintered at different temperatures viz. 700°C, 800°C, 900°C, 950°C, 1000°C, 1050°C materials is strong correlation between structure, transport and magnetic
for 2 hours. The grain size was calculated by Debye Scherrer‘s formula. The grain sizes properties.
were found to be 16nm, 17nm, 19nm, 20nm, 22nm, 35nm for all the samples. The samples
p.chhelavda@rediffmail.com were characterized by XRD, SEM, FTIR and EDAX. The phase contents and lattice  CMR materials have various potential applications such as magnetic random
parameters were studied by XRD. Morphological and grain size studies were done through access memories, read heads forMR(%)disks drives and also magnetic field
hard = ∆ρ
SEM. Chemical bonds were identified by FTIR Spectroscopy. Elemental compositions were
CMR & HTSC Laboratory, done through EDAX. This method is effective and can be easily quantitatively controlled
sensors. /ρ(H)=
Department of Physics, to synthesize nanosized perovskite type complex oxides. ρ(0) – ρ(H) /
Saurashtra University, ρ(H)
.
Rajkot – 360 005.
Results & Discussion CN-Gel Technique Results & Discussion
Fourier Transform Infrared Spectroscopy Scanning Electron Microscopy
NSMO700 NSMO800 NSMO900
NSMO-GEL NSMO700 NSMO800
NSMO1000 NSMO1050
NSMO900 NSMO1000 NSMO1050
750 700
2975-2840 cm-1 720-722cm-1
Symmetric (C-H) 1490-1440 cm-1 CH2 rocking
stretching Scissoring Absorption is
1390-1370 cm-1
Asymmetric (C-H) vibration 720 cm-1
Symmetric deformat-
stretching (CH3) ion-CH3 vibration
vibration
CH3, CH2 methyl group
Results & Results & Discussion
X-Ray Diffraction
Discussion Energy Dispersive X-Ray Analysis
Nd0.7Sr0.3MnO3
Conclusion References
 We could successfully prepared the samples of NSMO using polymeric citrate 1. Jin, S. et al. Science 264, 413 (1994).
precursor route at lower sintering temperatures compare to the samples prepared
by solid state reaction method.
2. R. Kajimoto, H.Yoshizawa, H. Kawano, H. Kuwahara, Y. Tokura, K.
 Samples sintered at 700°C and above temperatures upto 1050°C are good quality
Ohoyama, and M. Ohashi, Phys. Rev. B60, 403 (1951).
without additional phase or impurities. XRD study shows that the samples sintered
at various temperatures show neodymium strontium manganate to be the only 3. T. Venkatesan, M. Rajeswari, Z. W. Dong, S. B. Ogale and R. Ramesh,
crystalline phase NSMO (orthorhombic). The particle size is in the range of 16-35
nm for the samples. Phil. Trans. R. Soc Land. A 356, 1661 (1998).
Scherrer’s Formula :T= k λ/BCosθ  SEM micrographs show uniform grain growth. The homogeneous packing of tiny 4. G. J. Synder, R. Hiskes, S. Dicarolis, M. R. Beasley and T. H. Geballe,
crystalline aggregates favors a high sintering activity in the resultant powder. Phys. Rev. B53, 14434 (1996).
Structure: Orthorhombic
 Clean FTIR spectra are observed for the samples sintered at 700°C and above 5. M. Ziese. Rep Prog. Phys. 65, 143 (2002).
Space Group: with some unwanted backgrounds.
Pnma Acknowledgements
Lattice Parameters:  This method is effective and can be easily quantitatively controlled to
a=5.4259Å synthesize nanosized perovskite-type complex oxides. Authors are thankful to the departmental SAP-DRS
b=7.6635 Å programme and Gujarat Government sponsored Experimental
c=5.4907 Å Facilities for this work.