University of Illinois Urbana-Champaign

A powder neutron scattering study of magnetism in potassium copper trifluoride as a function of hydrostatic pressure

Nguyen, Brian Tuan-anh

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https://hdl.handle.net/2142/102421

Description

Title
A powder neutron scattering study of magnetism in potassium copper trifluoride as a function of hydrostatic pressure
Author(s)
Nguyen, Brian Tuan-anh
Issue Date
2018-11-08
Director of Research (if dissertation) or Advisor (if thesis)
  • MacDougall, Gregory J.
  • Gruebele, Martin
Department of Study
Chemistry
Discipline
Chemistry
Degree Granting Institution
University of Illinois at Urbana-Champaign
Degree Name
M.S.
Degree Level
Thesis
Keyword(s)
  • neutron scattering
  • magnetism
  • powder
  • pressure
  • kcuf3
Abstract
Presented here are elastic neutron scattering pressure studies investigating the magnetic ordering of KCuF3 under hydrostatic pressure. Recent studies have predicted the magnetic ordering to be modified at P ~ 7 kbar due to a glassy structural transition. Single crystal studies by Alexander Thaler of the MacDougall lab indicated relative peak intensities of the (001) and (003) magnetic Bragg peaks were not suppressed with pressure. Interestingly, the suppression of the (201) magnetic Bragg peak was observed. These results are believed to be due to a spin reorientation caused by a uniaxial strain component caused by using a clamp cell. Single crystal measurements also identified that the Néel temperature increased by approximately 1.6 K with 1.07 GPa applied pressure. We were motivated to further investigate the magnetic ordering of KCuF3 in a manner which mitigates the effect of the uniaxial strain on the magnetic properties of the material. Therefore, powder measurements were performed in various cell types. My work found that the ordered moment in powder samples under pressure does not appear to significantly change the magnetic ordering in this material up to P ~ 8 kbar, suggesting that the prediction of modified magnetic ordering due to a glassy structural transition does not occur.
Graduation Semester
2018-12
Type of Resource
text
Permalink
http://hdl.handle.net/2142/102421
Copyright and License Information
Copyright 2018 Brian Nguyen

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