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arXiv · 1901.11118

Tuning the Magnetic Ordering Temperature of Hexagonal Ferrites by Structural Distortion Control

Kishan Sinha·Haohan Wang·Xiao Wang·Liying Zhou·Yuewei Yin·Wenbin Wang·Xuemei Cheng·David J Keavney·Huibo Cao·Yaohua Liu·Xifan Wu·Xiaoshan Xu
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Abstract

To tune the magnetic properties of hexagonal ferrites, a family of magnetoelectric multiferroic materials, by atomic-scale structural engineering, we studied the effect of structural distortion on the magnetic ordering temperature (TN). Using the symmetry analysis, we show that unlike most antiferromagnetic rare-earth transition-metal perovskites, a larger structural distortion leads to a higher TN in hexagonal ferrites and manganites, because the K3 structural distortion induces the three-dimensional magnetic ordering, which is forbidden in the undistorted structure by symmetry. We also revealed a near-linear relation between TN and the tolerance factor and a power-law relation between TN and the K3 distortion amplitude. Following the analysis, a record-high TN (185 K) among hexagonal ferrites was predicted in hexagonal ScFeO3 and experimentally verified in epitaxially stabilized films. These results add to the paradigm of spin-lattice coupling in antiferromagnetic oxides and suggests further tunability of hexagonal ferrites if more lattice distortion can be achieved.

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Kishan Sinha, Haohan Wang, Xiao Wang, Liying Zhou, Yuewei Yin, Wenbin Wang, Xuemei Cheng, David J Keavney, Huibo Cao, Yaohua Liu, Xifan Wu, Xiaoshan Xu. 2019-01-30. Tuning the Magnetic Ordering Temperature of Hexagonal Ferrites by Structural Distortion Control. https://doi.org/10.1103/physrevlett.121.237203

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