A Pressure-Induced Inverse Order-Disorder Transition in Double Perovskites
Abstract
Given the consensus that pressure improves cation ordering in most of known materials, a discovery of pressure-induced disordering could require recognition of an order-disorder transition in solid-state physics/chemistry and geophysics. Double perovskites Y2CoIrO6 and Y2CoRuO6 polymorphs synthesized at 0, 6, and 15 GPa show B-site ordering, partial ordering, and disordering, respectively, accompanied by lattice compression and crystal structure alteration from monoclinic to orthorhombic symmetry. Correspondingly, the long-range ferrimagnetic ordering in the B-site ordered samples are gradually overwhelmed by B-site disorder. Theoretical calculations suggest that unusual unit-cell compressions under external pressures unexpectedly stabilize the disordered phases of Y2CoIrO6 and Y2CoRuO6.
- Publication:
-
Angewandte Chemie
- Pub Date:
- May 2020
- DOI:
- 10.1002/ange.202001922
- arXiv:
- arXiv:2003.08025
- Bibcode:
- 2020AngCh.132.8317D
- Keywords:
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- Condensed Matter - Materials Science;
- Condensed Matter - Strongly Correlated Electrons
- E-Print:
- 12 pages, 4 figures, 1 table