Year: 2019
Type: article
Abstract: We report on negative thermal expansion (NTE) in the high-field, half-magnetization plateau phase of the frustrated magnetic insulator CdCr_{2}O_{4}. Using dilatometry, we precisely map the phase diagram at fields of up to 30 T and identify a strong NTE associated with the collinear half-magnetization plateau for B>27 T. The resulting phase diagram is compared with a microscopic theory for spin-lattice coupling, and the origin of the NTE is identified as a large negative change in magnetization with temperature, coming from a nearly localized band of spin excitations in the plateau phase. These results provide useful guidelines for the discovery of new NTE materials.
Source: Physical Review Letters
Institutions: Radboud University Nijmegen, Max Planck Institute for Chemical Physics of Solids, The University of Tokyo, Institute for Solid State Physics and Optics, HUN-REN Wigner Research Centre for Physics, Hungarian Academy of Sciences, Okinawa Institute of Science and Technology Graduate University, Technical University of Munich, Kyoto University
Language: English
Subfield: Condensed Matter Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: bronze
Awards: G142100656, G3381134540
OpenAlex ID: W2962390846