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

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.

Name thesis:degree_name

M.S.

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Chemistry

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2019

Author dc:creator

• Nguyen, Brian Tuan-anh

Contributors dc:contributor

• MacDougall, Gregory J.
• Gruebele, Martin

• neutron scattering
• magnetism
• powder
• pressure
• kcuf3

Statement dc:rights

• Copyright 2018 Brian Nguyen

Language dc:language

en

Handle dc:identifier

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

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/102421