Neutron scattering is a technique that uses neutron beams to investigate the structure and dynamics of materials. It can be used to determine crystal structures, locate light and heavy atoms, study magnetic properties, and analyze atomic vibrations. Neutrons interact with atomic nuclei rather than electron clouds, allowing the differentiation of light atoms and isotopes. This information is obtained by measuring the scattering pattern produced as neutrons interact with a sample. Data analysis involves Fourier transformation and fitting to models to characterize features like particle size, shape, and interactions.
Neutron diffraction is the application of neutron scattering to the determination of atomic/ magnetic structure of a material. The technique is similar to XRD but the different type of radiation gives complementary radiation. It is of different types and overcomes the demerit of XRD. It has a lot of applications such as structure determination, locating light atoms, magnetic properties study, study of atomic vibration and other excitations.
Neutron diffraction is the application of neutron scattering to the determination of atomic/ magnetic structure of a material. The technique is similar to XRD but the different type of radiation gives complementary radiation. It is of different types and overcomes the demerit of XRD. It has a lot of applications such as structure determination, locating light atoms, magnetic properties study, study of atomic vibration and other excitations.
NQR - DEFINITION - ELECTRIC FIELD GRADIENT - NUCLEAR QUADRUPOLE MOMENT - NUCLEAR QUADRUPOLE COUPLING CONSTANT - PRINCIPLE OF NQR - ENERGY OF INTERACTION - SELECTION RULE - FREQUENCY OF TRANSITION - APPLICATIONS
Optical band gap measurement by diffuse reflectance spectroscopy (drs)Sajjad Ullah
Introduction to Optical band gap measurement
by electronic spectroscopy and diffuse reflectance spectroscopy (DRS) with comparison of the results obtained suing different equation and measurement techniques.
The role of scattering in extinction of light as it passes through media is briefly discussed.
Photoelectron spectroscopy
- a single photon in/ electron out process
• X-ray Photoelectron Spectroscopy (XPS)
- using soft x-ray (200-2000 eV) radiation to
examine core-levels.
• Ultraviolet Photoelectron Spectroscopy (UPS)
- using vacuum UV (10-45 eV) radiation to
examine valence levels.
NQR - DEFINITION - ELECTRIC FIELD GRADIENT - NUCLEAR QUADRUPOLE MOMENT - NUCLEAR QUADRUPOLE COUPLING CONSTANT - PRINCIPLE OF NQR - ENERGY OF INTERACTION - SELECTION RULE - FREQUENCY OF TRANSITION - APPLICATIONS
Optical band gap measurement by diffuse reflectance spectroscopy (drs)Sajjad Ullah
Introduction to Optical band gap measurement
by electronic spectroscopy and diffuse reflectance spectroscopy (DRS) with comparison of the results obtained suing different equation and measurement techniques.
The role of scattering in extinction of light as it passes through media is briefly discussed.
Photoelectron spectroscopy
- a single photon in/ electron out process
• X-ray Photoelectron Spectroscopy (XPS)
- using soft x-ray (200-2000 eV) radiation to
examine core-levels.
• Ultraviolet Photoelectron Spectroscopy (UPS)
- using vacuum UV (10-45 eV) radiation to
examine valence levels.
X ray crystallography to visualize protein structure.Ritam38
This ppt discusses in detail the process of X ray Crystallography.
Made by the following 3rd year Bs-Ms students of IISER Kolkata:
B Sri Sindhu
Rasiwala Hassan Shabbir
Ritam Samanta
Himanshu Gupta
Sakshi Ajay Shrisath
Aditya Borkar
Diana Denzil Fernandez
Neha Kumari
.Sowmya
Anjali Mohan
Debanjana Mondal
Aanandita Gope
Shruti Santosh Sail
Calculation of Optical Properties of Nano ParticlePHYSICS 5535- .docxRAHUL126667
Calculation of Optical Properties of Nano Particle
PHYSICS 5535- Optical Properties Matter-Spring 2017
Raznah Yami
Outline
1. Introduction: this part gives a precise overview of the whole paper. It begins by illustrating a brief introduction and importance of Nano Particles and the theoretical approaches used for their calculation.
2. Main idea: this section provides a step-by-step in-depth analysis of recently developed theories the calculation of optical properties of nanoparticles. It also provides calculation and equations employed these approaches.
2.1 Optical Properties of Nanoparticles: this section talks about the basics principles and governing the optical behavior of Nano particles and provides in-depth knowledge of different phenomena observed while dealing with optical properties of Nano particles.
2.2 Mie-Theory: the research provides exhaustive information the study optical properties of nanoparticles using Mie theory. This research focuses on Mie theory for the calculation of optical properties of Nano particle according to which we can calculate the place of surface Plasmon resonance in optical spectra of metallic spherical nanoparticle.
2.3 Discrete Dipole Approximation method: this section enumerates sufficient information about the calculation of absorption and scattering efficiencies and optical resonance wavelengths for three commonly used classes of nanoparticles: gold Nano spheres, silica-gold Nano shells, and gold Nano rods and we examine the magneto-optical scattering from nanometer-scale structures using a discrete dipole approximation.
3. Conclusion: This section provides a summary of the most important points, which presents an overview of the practical application and calculation methods of optical properties of Nano particles talking about core principles, which therefore explain the behavior exhibited by nanoparticles.
List of figures:
Figure 1: Localized surface Plasmon resonance ,resulting from the collective oscillations of delocalized electrons in response to an external electric field
Figure 2: Absorption spectra of semiconductor nanoparticles of different diameter. Right-nanoparticles suspended in solution.
Figure 3: Comparison of absorbance along increasing wavelength between Nano GaAs (7-15 nm) and Bulk GaAs showing an apparent blue shift
Figure 4: Showing the effect of blue shift because of quantum confinement as the wavelength shifts from 1100 nm to 2000 nm when we move from particle size of 9nm to parcile size of 3 nm.
Figure 5: Emission spectra of several sizes of (Cdse) Zns core-shell quantum dots.
Figure 6: The optical spectra and transmission electron micrographs for the particles in vials 1–5 are also shown. Scale bars in micrographs are all 100 nm
Figure7: Shows the effect of varying relative core and shell thickness of gold Nano Shells, there is an apparent blue shift as the frequency increases
References:
1. . P. S. Per ...
Electron Diffraction Using Transmission Electron MicroscopyLe Scienze Web News
Electron diffraction via the transmission electron microscope is a powerful method for characterizing the structure of materials, including perfect crystals and defect structures. The advantages of elec- tron diffraction over other methods, e.g., x-ray or neutron, arise from the extremely short wavelength (≈2 pm), the strong atomic scattering, and the ability to exam- ine tiny volumes of matter (≈10 nm3). The NIST Materials Science and Engineer- ing Laboratory has a history of discovery and characterization of new structures through electron diffraction, alone or in combination with other diffraction methods. This paper provides a survey of some of this work enabled through electron mi- croscopy.
Welcome to TechSoup New Member Orientation and Q&A (May 2024).pdfTechSoup
In this webinar you will learn how your organization can access TechSoup's wide variety of product discount and donation programs. From hardware to software, we'll give you a tour of the tools available to help your nonprofit with productivity, collaboration, financial management, donor tracking, security, and more.
Operation “Blue Star” is the only event in the history of Independent India where the state went into war with its own people. Even after about 40 years it is not clear if it was culmination of states anger over people of the region, a political game of power or start of dictatorial chapter in the democratic setup.
The people of Punjab felt alienated from main stream due to denial of their just demands during a long democratic struggle since independence. As it happen all over the word, it led to militant struggle with great loss of lives of military, police and civilian personnel. Killing of Indira Gandhi and massacre of innocent Sikhs in Delhi and other India cities was also associated with this movement.
Instructions for Submissions thorugh G- Classroom.pptxJheel Barad
This presentation provides a briefing on how to upload submissions and documents in Google Classroom. It was prepared as part of an orientation for new Sainik School in-service teacher trainees. As a training officer, my goal is to ensure that you are comfortable and proficient with this essential tool for managing assignments and fostering student engagement.
Model Attribute Check Company Auto PropertyCeline George
In Odoo, the multi-company feature allows you to manage multiple companies within a single Odoo database instance. Each company can have its own configurations while still sharing common resources such as products, customers, and suppliers.
The Art Pastor's Guide to Sabbath | Steve ThomasonSteve Thomason
What is the purpose of the Sabbath Law in the Torah. It is interesting to compare how the context of the law shifts from Exodus to Deuteronomy. Who gets to rest, and why?
2024.06.01 Introducing a competency framework for languag learning materials ...Sandy Millin
http://sandymillin.wordpress.com/iateflwebinar2024
Published classroom materials form the basis of syllabuses, drive teacher professional development, and have a potentially huge influence on learners, teachers and education systems. All teachers also create their own materials, whether a few sentences on a blackboard, a highly-structured fully-realised online course, or anything in between. Despite this, the knowledge and skills needed to create effective language learning materials are rarely part of teacher training, and are mostly learnt by trial and error.
Knowledge and skills frameworks, generally called competency frameworks, for ELT teachers, trainers and managers have existed for a few years now. However, until I created one for my MA dissertation, there wasn’t one drawing together what we need to know and do to be able to effectively produce language learning materials.
This webinar will introduce you to my framework, highlighting the key competencies I identified from my research. It will also show how anybody involved in language teaching (any language, not just English!), teacher training, managing schools or developing language learning materials can benefit from using the framework.
How to Split Bills in the Odoo 17 POS ModuleCeline George
Bills have a main role in point of sale procedure. It will help to track sales, handling payments and giving receipts to customers. Bill splitting also has an important role in POS. For example, If some friends come together for dinner and if they want to divide the bill then it is possible by POS bill splitting. This slide will show how to split bills in odoo 17 POS.
The Roman Empire A Historical Colossus.pdfkaushalkr1407
The Roman Empire, a vast and enduring power, stands as one of history's most remarkable civilizations, leaving an indelible imprint on the world. It emerged from the Roman Republic, transitioning into an imperial powerhouse under the leadership of Augustus Caesar in 27 BCE. This transformation marked the beginning of an era defined by unprecedented territorial expansion, architectural marvels, and profound cultural influence.
The empire's roots lie in the city of Rome, founded, according to legend, by Romulus in 753 BCE. Over centuries, Rome evolved from a small settlement to a formidable republic, characterized by a complex political system with elected officials and checks on power. However, internal strife, class conflicts, and military ambitions paved the way for the end of the Republic. Julius Caesar’s dictatorship and subsequent assassination in 44 BCE created a power vacuum, leading to a civil war. Octavian, later Augustus, emerged victorious, heralding the Roman Empire’s birth.
Under Augustus, the empire experienced the Pax Romana, a 200-year period of relative peace and stability. Augustus reformed the military, established efficient administrative systems, and initiated grand construction projects. The empire's borders expanded, encompassing territories from Britain to Egypt and from Spain to the Euphrates. Roman legions, renowned for their discipline and engineering prowess, secured and maintained these vast territories, building roads, fortifications, and cities that facilitated control and integration.
The Roman Empire’s society was hierarchical, with a rigid class system. At the top were the patricians, wealthy elites who held significant political power. Below them were the plebeians, free citizens with limited political influence, and the vast numbers of slaves who formed the backbone of the economy. The family unit was central, governed by the paterfamilias, the male head who held absolute authority.
Culturally, the Romans were eclectic, absorbing and adapting elements from the civilizations they encountered, particularly the Greeks. Roman art, literature, and philosophy reflected this synthesis, creating a rich cultural tapestry. Latin, the Roman language, became the lingua franca of the Western world, influencing numerous modern languages.
Roman architecture and engineering achievements were monumental. They perfected the arch, vault, and dome, constructing enduring structures like the Colosseum, Pantheon, and aqueducts. These engineering marvels not only showcased Roman ingenuity but also served practical purposes, from public entertainment to water supply.
Read| The latest issue of The Challenger is here! We are thrilled to announce that our school paper has qualified for the NATIONAL SCHOOLS PRESS CONFERENCE (NSPC) 2024. Thank you for your unwavering support and trust. Dive into the stories that made us stand out!
This is a presentation by Dada Robert in a Your Skill Boost masterclass organised by the Excellence Foundation for South Sudan (EFSS) on Saturday, the 25th and Sunday, the 26th of May 2024.
He discussed the concept of quality improvement, emphasizing its applicability to various aspects of life, including personal, project, and program improvements. He defined quality as doing the right thing at the right time in the right way to achieve the best possible results and discussed the concept of the "gap" between what we know and what we do, and how this gap represents the areas we need to improve. He explained the scientific approach to quality improvement, which involves systematic performance analysis, testing and learning, and implementing change ideas. He also highlighted the importance of client focus and a team approach to quality improvement.
2. Outlines
Introduction
Application
Why neutron
Neutron VS X ray
Types of neutron scattering
Theory
Instrumentation
Fitting
Data
Pros and Cons
3. Scattering of free neutrons by matter reffer
to.
Physical process or experimental
technique which uses this process for
material investigation
As physical process
Primordial importance in neuclear
engineering
As exeprimental technique used in
Crystallography
Neutron
scattering
4. Application of Neutron
diffraction
Used for determination of structure
Locating Light atoms
Heavy atoms that absorb x-ray strongly
Similar atomic no /Isotopes
Magnetic properties
Single crystal studies analysis
Inelastic scattering Used for study of atomic
vibration and other excitations
5. Neutrons
Neutron Are Wave
Beam of neutrons incident on sample
Distribution of radiation scattered from sample
measured
This is determined by interaction potential and
momentum transfer b/w the beam and sample
6. Why neutrons ?
• No charge
• High energy
• Strong magnetic interaction
• Scatter strongly from light nuclei
7. Neutron Vs X-ray
Neutron X-ray
Highly penetrating due to their 0
charge. Therefore can probe the
internal structure of materials
No charge, and provides data on the
surface structure mainly
Interacts with nuclei, and therefore
scatters strongly from light atoms,
as well as heavy atoms, and can
differentiate easily between
isotopes
Interacts with the electron clouds,
and therefore scatters strongly from
heavier elements with larger
electron clouds.
Neutrons are spin- ½ particles, and
carry a magnetic moment (good to
study magnetism over short ranges)
Can be used to study magnetism,
through electromagnetic radiation,
but provide less information.
Expensive!!!! Less expensive
Requires the use of high energy
synchrotron rings
Can be done in house
8. Types of neutron experiment
Diffraction/ elastic scattering
-no energy transfer to/from sample
- crystal structure ,atomic correlation in liguid
/glass
Inelastic scattering
-energy transfer to/from sample
- Measurment of lattice vibration (phonons),atomic
difusion,molecular modes
Small angle scattering
-diffraction at small angle
-measure large molecule protein ,colloid,
nanoparticle etc
Reflectrometry
Diffraction from surface speculars or off specullar
Measure depth profile of thin film ,membrane
Imaging
9. Theory
Scattering of neutrons at small angles gives
information about their structure and size, giving a
scattering pattern
This pattern is subjected to Fourier Transformation,
and described in terms of a momentum transfer
vector (Q), instead of a diffraction angle.
Q is scattering in reciprocal space, rather than actual
(d) space.
Small Q values look at long distances, large Q values
look at short distances.
Q values of 0.006 to 0.28 Å-1 probes distances of
about 10 to 1000 Å ( 1 to 100 nm ).
10. Sample preparation
All samples need to be made in D20.
Samples can be contrast matched, allowing for
parts of the sample to become invisible to the
neutron beam.
Contrast variation involves matching the density
of part of the sample, with ratios of D2O and H2O.
All samples need to be placed in clean quartz
cuvettes, and placed in the instrument.
12. Fitting
Many fitting programmes available:
SASview
Fish
SASfit
Fitting based on prior knowledge about
system, and uses other experimentally
determined values
13. The data
• The data generated provides info on the shape and
structure (but needs to be fitted).
• Changes in Q (the wiggles) define a change in scatering
length density
• From this, the data can be fitted to different models,
which can provide information on the size of the particle,
interactions, radius of rotation, structure, shape etc…
14. Pros and Cons
Pro’s Con’s
Powerful technique to characterise
internal and external structural features
Requires previous knowledge on
system from other techniques
Contrast matching can make parts of
the system “invisible”
Requires knowledge on the density of
different parts of the system
Very good at looking at probing size
and structural effects in “smart”
systems
Looking at samples in different
conditions is time consuming. Only a
limited amount of beam time is available
Good in characterisation of simple
systems (e.g. sphecircal
particles/polymers), up to very complex
systems in complicated sample
environments (e.g. temperature
responsive nanoparticles in a
supercritical environment)
Data fitting gets more complicated as
more parameters are added to a system,
which requires more previous
knowledge
Looks very good in papers, and
increases the impact of the article
Need to apply for beam time
Can be used for many types of particle
in many different environments
Specific fields requires more expertise
in the area e.g. biological samples.