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dc.creatorNewhouse, Randal Leslie
dc.date.accessioned2012-10-23T17:18:18Z
dc.date.available2012-10-23T17:18:18Z
dc.date.issued2012-08
dc.identifier.urihttp://hdl.handle.net/2376/4186
dc.descriptionThis report includes the PhD dissertation or Randal Leslie Newhouse, defended May 16, 2012. An addendum is attached at the end of the report that includes additional findings in the dissertation research. The research described herein was supported in part by the National Science Foundation under grants DMR 05-04843 and 09-04096 (Metals Program).en_US
dc.description.abstractAtomic jump frequencies were determined in a variety of intermetallic compounds through analysis of nuclear relaxation of spectra measured using the nuclear hyperfine technique, perturbed angular correlation (PAC) of gamma rays. Observed at higher temperatures, this relaxation is attributed to fluctuations in the orientation or magnitude of electric field gradients (EFG) at nuclei of 111In/Cd probe atoms as the atoms make diffusive jumps. Jump frequencies were obtained by fitting dynamically relaxed PAC spectra using either an empirical relaxation function or using ab initio relaxation models created using the program PolyPacFit. Jump frequency activation enthalpies were determined from measurements over a range of temperatures. Diffusion was studied in the following systems: 1) Pseudo-binary alloys having the L12 crystal structure such as In3(La1-xPrx). The goal was to see how jump frequencies were affected by random disorder. 2) The family of layered phases, LanCoIn3n+2 (n=0,1,2,3…∞). The goal was to see how jump frequencies varied with the spacing of Co layers, which were found to block diffusion. 3) Phases having the FeGa3 structure. The goal was to analyze dynamical relaxation for probe atoms having multiple inequivalent jump vectors. 4) Phases having the tetragonal Al4Ba structure. The goal was to search for effects in the PAC spectra caused by fluctuations in magnitudes of EFGs without fluctuations in orientations. Ab initio relaxation models were developed to simulate and fit dynamical relaxation for PAC spectra of FeGa3, and several phases with the Al4Ba structure in order to determine underlying microscopic jump frequencies. In the course of this work, site preferences also were observed for 111In/Cd probe atoms in several FeGa3 and Al4Ba phases.en_US
dc.description.sponsorshipNational Science Foundation; Hyperfine Interactions Group, Department of Physics & Astronomy, Washington State Universityen_US
dc.languageEnglish
dc.relation.ispartofseriesNational Science Foundation Grant DMR 09-04096 Metals Program Technical Report;4
dc.rightsIn copyright
dc.rightsPublicly accessible
dc.rightsopenAccess
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/
dc.rights.urihttp://www.ndltd.org/standards/metadata
dc.rights.urihttp://purl.org/eprint/accessRights/OpenAccess
dc.subjectgamma rays
dc.subjectintermetallic compounds
dc.subjectatomic jump frequencies
dc.subjectdynamic relaxation
dc.subjectEFG magnitude
dc.subjectelectric field gradients
dc.titleAtomic jump frequencies in intermetallic compounds studied using perturbing angular correlation of gamma rays
dc.typeTechnical Report
dc.typeText


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