1. Charge and spin order in Ca0.5Bi0.5FeO3: Idle spins and frustration in the charge-disproportionated state.
- Author
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Romero, Fabio Denis, Yoshiteru Hosaka, Noriya Ichikawa, Takashi Saito, McNally, Graham, Attfield, J. Paul, and Yuichi Shimakawa
- Subjects
- *
PHYSICS periodicals , *PEROVSKITE , *CHARGE transfer - Abstract
The perovskite Ca0.5Bi0.5FeO3 undergoes a remarkable sequence of charge-disproportionation (CD) and charge-transfer (CT) transitions on cooling due to competing electronic instabilities: Ca0.5Bi3+0.5Fe3.5+O3→Ca0.5Bi3+0.5Fe3+0.67Fe4.5+0.33O3(CDphase)→Ca0.5Bi3+0.25Bi5+0.25Fe3+O3(CTphase). The accompanying changes in charge and spin ordering have been determined from neutron diffraction and physical property measurements. The CT phase adopts a simple G-type antiferromagnetic structure of Fe3+ spins but the CD phase adopts an unusual charge and magnetic arrangement in which Fe3+ spins are antiferromagnetically ordered but the Fe4.5+ moments have no long-range order due to magnetic frustration and form a spin glass at low temperatures. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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