Scientific and Technical Aerospace Reports


Book Description

Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.







Magnetic Neutron Scattering: Proceedings Of The Third Summer School On Neutron Scattering


Book Description

The proceedings provide a topical survey of the static and dynamical magnetic properties of condensed matter studied by neutron scattering which has been the key technique in this field for a long time. The static aspects deal with the determination of long-range ordered spin structures and magnetization densities. The dynamic aspects concentrate on the determination of magnetic excitations such as spin waves and crystal-field transitions. The use of polarized-neutron techniques is particularly emphasized. All these topics are thoroughly introduced, methodically discussed, and highlighted with recent experimental results obtained for a vast variety of magnetic materials (e.g., strongly correlated electron systems, multilayers, nanocrystals, molecular complexes, etc.) by acknowledged experts. Other experimental methods (x-ray scattering, muon spin rotation) in the study of magnetism are compared to neutron scattering.










X-ray and Neutron Scattering Studies of Magnetic Domain Dynamics and Spin Structures


Book Description

The study of magnetic spin structures at nanometer length scales and their dynamics is of both fundamental and technological importance. X-rays and neutrons are penetrating probes that are suitable for studying these in the bulk and the interfaces of the materials. In this thesis, the magnetic domain dynamics are studied by resonant soft x-ray scattering together with x-ray photon correlation spectroscopy. The domain fluctuations reveal when the temperature is close to the phase transition temperature. We find the domain wall dynamics in an antiferromagnet corresponds to a collective motion of spins and exhibit some universal features associated with the jamming behavior in many jammed soft condensed matter systems. We also discuss about the utilization of polarized neutron reflectometry to study the interfacial spin structure in an exchange biased bilayer. The magnetization profiles are obtained which show that some spins are not completely reversible when the magnetic field is reversed. These spins include pinned uncompensated spins in the antiferromagnet and the interfacial spins exchange coupled to those spins. A previously established model was found to reproduce the magnetization profile observed. Finally, we carried out a grazing incidence small angle neutron scattering experiment on an optical grating as a way to test the Distorted Wave Born Approximation (DWBA). DWBA is briefly reviewed and we used it to calculate the scattering intensity of the system.