| Autor: |
Kemei MC; Materials Department and Materials Research Laboratory, University of California, Santa Barbara, CA 93106, USA. kemei@mrl.ucsb.edu, Barton PT, Moffitt SL, Gaultois MW, Kurzman JA, Seshadri R, Suchomel MR, Kim YI |
| Jazyk: |
angličtina |
| Zdroj: |
Journal of physics. Condensed matter : an Institute of Physics journal [J Phys Condens Matter] 2013 Aug 14; Vol. 25 (32), pp. 326001. Date of Electronic Publication: 2013 Jul 12. |
| DOI: |
10.1088/0953-8984/25/32/326001 |
| Abstrakt: |
Magnetic ordering in the geometrically frustrated magnetic oxide spinels MgCr2O4 and ZnCr2O4 is accompanied by a structural change that helps to relieve the frustration. Analysis of high-resolution synchrotron x-ray scattering reveals that the low-temperature structures are well described by a two-phase model of tetragonal I41/amd and orthorhombic Fddd symmetries. The Cr4 tetrahedra of the pyrochlore lattice are distorted at these low-temperatures, with the Fddd phase displaying larger distortions than the I41/amd phase. The spin-Jahn-Teller distortion is approximately one order of magnitude smaller than is observed in first-order Jahn-Teller spinels such as NiCr2O4 and CuCr2O4. In analogy with NiCr2O4 and CuCr2O4, we further suggest that the precise nature of magnetic ordering can itself provide a second driving force for structural change. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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