The Study of Lattice Dynamics in Crystalline Material using Inelastic Neutron Scattering
Inelastic neutron scattering is an experimental method that is used to observe and measure the micro-vibration (dynamics) of atoms and spins in a sample material. By observing the difference in energy between the incident and scattered neutrons, the magnitudes, distances, and directions of the forces acting between the atoms or spins in the sample can be determined.
In this course, students will measure atomic vibrations (phonons) in a single crystal by inelastic neutron scattering using the chopper spectrometer 4SEASONS. By analyzing the data, students will learn what kinds of forces act between atoms and how they affect the macroscopic properties.
The Study of Molecular Dynamics on the Nanosecond Timescale using Quasielastic Neutron Scattering
Quasielastic neutron scattering is considered to be one of the most effective techniques for measuring the dissipation motion (e.g. fluctuation or diffusion) of atoms, molecules and spins in a material. In particular, in a number of widely-used functional materials, such as in lithium secondary batteries or fuel cells, solid state ionic conductors play an important role. In these solid state ionic conductors, the ions or hydrogen atoms are moving at a speed similar to that of the liquid state, even at around room temperature. These dynamic motions of ions and hydrogen atoms can be measured at the nanosecond timescale using quasi-elastic neutron scattering.
In this course, students will use the DNA high-resolution spectrometer to study the hydrogen ion dynamics in a Nafion ion exchange membrane, a material that is currently in practical use in polymer electrolyte fuel cells. At the same time, students will learn how to analyze the data from a typical quasielastic neutron scattering experiment.
IBARAKI Biological Crystal Diffractometer
Using Single Crystal Neutron Diffraction to Study Bio-macromolecules
Neutron diffraction is a powerful method for determining and studying the arrangement of atoms in crystalline materials. By measuring the so-called “Bragg reflections” that arise from neutrons scattered by single crystals, a detailed picture of the sample structure at the atomic level can be derived. The Ibaraki biological crystal diffractometer iBIX (BL03) is an instrument designed for single crystal neutron diffraction, specifically targeting the study of small organic molecules and bio-macromolecules.
In this course, students will use BL03 to measure the time-of-flight neutron diffraction data from a standard protein single crystal. They will also receive hands-on instruction on experimental methods, data reduction and structure analysis techniques with special emphasis on determining the location of hydrogen and deuterium atoms.
In-situ High Pressure Neutron Diffraction
Materials change their structure and physical properties under high pressure through the reduction of interatomic distances and the resulting changes in the vibrational states and/or band structure. To understand the origin of these changes, information on crystal structure at high pressures is indispensable.
In this course, participants will learn methods of applying the pressure to the sample and determining its crystal structure by Rietveld analysis through in-situ powder neutron diffraction experiments on a high-pressure phase of D2O ice at PLANET beamline.
Materials science and engineering studies using pulsed neutron diffraction in TAKUMI
TAKUMI is a TOF neutron powder diffractometer dedicated for materials science and engineering studies. Careful analysis of the Bragg peaks in a neutron diffraction pattern can reveal important structural details of a sample material such as internal stresses, phase fractions, dislocations, texture etc. Such information is often crucial in engineering applications and the ability to carry out either ex situ or in situ measurements makes neutron diffraction particularly useful in this respect.
In this course, the basics of materials science and engineering studies using neutron diffraction will be introduced and students will participate in trial experiments using TAKUMI and hands-on data analysis sessions. An in situ loading experiment of a metallic material will be performed as the trial experiment.
IBARAKI Materials Design Diffractometer
Decipher the Materials Structure of Interest
We are surrounded by materials with various functions. Functions of batteries, magnets, superconductors, multiferroic materials, optical & thermoelectric materials, soft materials, etc. are consequences of atomic structures & their changes with various characteristic scales.
In this course, we will learn about the method to decipher the atomic structures of functional materials using advanced neutron diffraction techniques. Understanding atomic structures are the first step in materials science. Students will conduct high resolution neutron diffraction experiments using the iMATERIA diffractometer at the beamline BL20 and will experience crystallographic analyses and the visualization of the atomic structures.
Structural Analysis using the Small and Wide Angle Neutron Scattering Instrument TAIKAN
The Small and Wide Angle Neutron Scattering Instrument TAIKAN can probe structures in materials on a correlation length scale from about 0.1 nm to over about 1,000 nm.
The following topics will be covered in this course:
· Simultaneous measurement of SANS and WANS using a pulsed neutron beam
· Similarities and differences between SANS using a pulsed beam, SANS using a continuous beam and SAXS
· Diversity of sample environments
· Experimental methods and data analysis procedures using samples such as nanoparticles, polymers, metals, magnetic materials, etc.
Surface and interface analysis using neutron reflectometry
As different materials meet at surfaces and interfaces, they show characteristic properties and various functions due to their peculiarity, which attract chemists, biologists, and physicists. Neutron reflectometry (NR) is a powerful tool for investigating the surface and interfaces of soft matters, magnetic materials etc. on the nanometer to sub-micrometer length scale with taking advantage of the unique characteristics of neutrons. Neutrons can distinguish an interesting part labeled with deuterium and/or can observe an interface between solid and liquid through a substrate. Moreover, by using a polarized neutron beam, the magnetic structure in magnetic thin films cab be analyzed. In this course, the students can learn the basic principle of the NR measurement and analysis in an experiment using SHARAKU.
Visualization of Structure and Physical Property Distributions Using Energy-Resolved Neutron Imaging
Neutron imaging is a widely-used, nondestructive investigation method to visualize the internal structure of objects. The energy-resolved neutron imaging technique using a pulsed neutron beam, where the energy dependent neutron transmission is carefully analyzed position by position, provides the spatial distribution of various information, such as elemental concentration and temperature by neutron resonance absorption imaging, crystallographic structure by Bragg-edge imaging, and magnetic field by polarized neutron imaging.
In this course, both conventional neutron imaging and energy-resolved neutron imaging will be introduced. Students will conduct demonstration experiments for both neutron imaging methods using the RADEN instrument (BL22), including data analysis and visualization of the results.
Positive muon spin relaxation (μSR)
Positive muon in a material stops at an interstitial site, observes magnetic fields of the environment and exhibits Larmor spin precession. By measuring the decay positrons emitted from muons, time dependent behavior of the muon spin in a material is known. This is the spectroscopy called (positive) muon spin relaxation (μSR). This technique yields the information of the magnetic property of a material, including magnetism and superconductivity and the hydrogen state in a material with the muon being a light hydrogen isotope.
In contrast to neutron, muon is a local magnetic probe in real space with a unique time scale, being a powerful probe of spin relaxation phenomena.
In this course, students will have an opportunity to actually perform μSR measurement at the S1-ARTEMIS spectrometer and will receive instruction of data analysis. Introductory lectures on μSR and other muon measurements will also be given as a part of the school.