Charge and spin order in Ca0.5Bi0.5FeO3: Idle spins and frustration in the charge-disproportionated state

Fabio Denis Romero, Yoshiteru Hosaka, Noriya Ichikawa, Takashi Saito, Graham McNally, J. Paul Attfield, Yuichi Shimakawa

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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: Ca0.5Bi0.53+Fe3.5+O3 -> Ca0.5Bi0.53+Fe0.673+Fe0.334.5+O3 (CD phase) -> Ca0.5Bi0.253+Bi0.255+Fe3+O3 (CT phase). 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.

Original languageEnglish
Article number064434
Number of pages5
JournalPhysical Review B
Issue number6
Early online date29 Aug 2017
Publication statusE-pub ahead of print - 29 Aug 2017


  • CAFEO3
  • IRON

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