Successive Charge Transitions of Unusually High-Valence Fe3.5+ : Charge Disproportionation and Intermetallic Charge Transfer

Yoshiteru Hosaka; Fabio Denis Romero; Noriya Ichikawa; Takashi Saito; Yuichi Shimakawa

doi:10.1002/anie.201700881

Successive Charge Transitions of Unusually High-Valence Fe^3.5+ : Charge Disproportionation and Intermetallic Charge Transfer

Angew Chem Int Ed Engl. 2017 Apr 3;56(15):4243-4246. doi: 10.1002/anie.201700881. Epub 2017 Mar 20.

Authors

Yoshiteru Hosaka¹, Fabio Denis Romero¹, Noriya Ichikawa¹, Takashi Saito¹, Yuichi Shimakawa¹

Affiliation

¹ Institute for Chemical Research, Kyoto University, Gokasho, Uji, Kyoto, 611-0011, Japan.

PMID: 28319301
DOI: 10.1002/anie.201700881

Abstract

A perovskite-structure oxide containing unusually high-valence Fe^3.5+ was obtained by high-pressure synthesis. Instability of the Fe^3.5+ in Ca_0.5 Bi_0.5 FeO₃ is relieved first by charge disproportionation at 250 K and then by intermetallic charge transfer between A-site Bi and B-site Fe at 200 K. These previously unobserved successive charge transitions are due to competing intermetallic and disproportionation charge instabilities. Both transitions change magnetic and structural properties significantly, indicating strong coupling of charge, spin, and lattice in the present system.

Keywords: Mössbauer spectroscopy; charge disproportionation; charge transfer; iron; perovskite phases.

Publication types

Research Support, Non-U.S. Gov't