Enhanced Magnetic Interaction by Face-Shared Hydride Anions in 6H-BaCrO2H

Published

August 16, 2021

Author(s)

Kentaro Higashi, Masayuki Ochi, Yusuke Nambu, Takafumi Yamamoto, Taito Murakami, Naoya Yamashina, Cedric Tassel, Yuki Matsumoto, Hiroshi Takatsu, Craig Brown, Hiroshi Kageyama

Abstract

Studies on magnetic oxyhydrides have been almost limited to perovskite-based lattices with corner-sharing octahedra with a M‒H‒M (M: transition metal) angle of θ 180 °. Using a high-pressure method, we prepared BaCrO₂H with a 6H-type hexagonal perovskite structure with corner- and face-sharing octahedra, offering a unique opportunity to investigate magnetic interactions based on a θ 90 ° case. Neutron diffraction on this compound revealed an antiferromagnetic (AFM) order at T_N 375 K. The relatively high T_N appears to be simply explained by the preferred occupancy of H^‒ at the face-sharing site that provides AFM superexchange in addition to AFM direct exchange interactions. However, first-principles calculations on BaCrO₂H in comparison with a hypothetical BaCrO₂F showed that the direct Cr–Cr interaction is significantly enhanced by shortening the Cr–Cr distance, which is probably due to the covalent nature of H^‒. This study provides a useful strategy for the extensive control of magnetic interactions by exploiting the difference in the covalency of multiple anions.

Citation

Inorganic Chemistry

Volume

60

Pub Type

Journals

Keywords

high-pressure synthesis, oxyhydride, hexagonal perovskites, superexchange, oxyfluoride

Citation

Higashi, K. , Ochi, M. , Nambu, Y. , Yamamoto, T. , Murakami, T. , Yamashina, N. , Tassel, C. , Matsumoto, Y. , Takatsu, H. , Brown, C. and Kageyama, H. (2021), Enhanced Magnetic Interaction by Face-Shared Hydride Anions in 6H-BaCrO₂H, Inorganic Chemistry (Accessed April 24, 2024)