Title: Magnetic correlations and structure in bixbyite across the spin-glass transition

Abstract

Magnetic frustration in atomically ordered crystals gives rise to a broad range of quantum phenomena. The mineral bixbyite, $\mathrm{F}{\mathrm{e}}_{2-x}\mathrm{M}{\mathrm{n}}_x{\mathrm{O}}_3$, has magnetic frustration induced by atomic disorder. The end-members $\mathrm{M}{\mathrm{n}}_2{\mathrm{O}}_3$ and $\beta -\mathrm{F}{\mathrm{e}}_2{\mathrm{O}}_3$ both have magnetically ordered ground states, but the bixbyite crystal studied here, with a composition $\mathrm{F}{\mathrm{e}}_{1.12}\mathrm{M}{\mathrm{n}}_{0.88}{\mathrm{O}}_3$, instead undergoes a spin-glass-like transition near 32 K. Here, the magnetic correlations and atomic structure of bixbyite are followed across the spin-glass transition using powder and single-crystal neutron scattering. Refinement of Bragg intensities from neutron diffraction data allows precise determination of the average Fe and Mn concentration on the different crystallographic sites of the structure. No structural transitions occur in bixbyite upon cooling. Using the three-dimensional magnetic difference pair distribution function (3D-mΔPDF), the magnetic correlations are resolved spatially and their temperature dependence determined. The results demonstrate that the spin-spin correlations are strong well above the glass transition temperature, consistent with the spin-glass nature of the magnetism in bixbyite.

Authors:

Roth, Nikolaj ^[1]; Ye, Feng  ^[2];

• Search DOE PAGES for author "Ye, Feng"
• Search DOE PAGES for ORCID "0000-0001-7477-4648"

May, Andrew F.  ^[3];

• Search DOE PAGES for author "May, Andrew F."
• Search DOE PAGES for ORCID "0000-0003-0777-8539"

Chakoumakos, Bryan C.  ^[2];

• Search DOE PAGES for author "Chakoumakos, Bryan C."
• Search DOE PAGES for ORCID "0000-0002-7870-6543"

Iversen, Bo Brummerstedt ^[1]

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+ Show Author Affiliations

1. Aarhus Univ. (Denmark). Dept. of Chemistry and Interdisciplinary Nanoscience Center (iNANO), Center for Materials Crystallography (CMC)
2. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Neutron Scattering Division
3. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science & Technology Division

Publication Date:

Wed Oct 02 00:00:00 EDT 2019

Research Org.:

Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Spallation Neutron Source (SNS)

Sponsoring Org.:

USDOE Office of Science (SC), Basic Energy Sciences (BES). Materials Sciences & Engineering Division; Danish National Research Foundation

OSTI Identifier:

1651358

Grant/Contract Number:  

AC05-00OR22725

Resource Type:

Accepted Manuscript

Journal Name:

Physical Review B

Additional Journal Information:

Journal Volume: 100; Journal Issue: 14; Journal ID: ISSN 2469-9950

Publisher:

American Physical Society (APS)

Country of Publication:

United States

Language:

English

Subject:

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; magnetic interactions; magnetism; spin glasses; transition-metal oxides