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arXiv · 1903.02490

Anomalous Magnetic Behavior in Ba2CoO4 with Isolated CoO4 Tetrahedra

Qiang Zhang·Guixin Cao·Feng Ye·Huibo Cao·Masaaki Matsuda·D. A. Tennant·Songxue Chi·S. E. Nagler·W. A. Shelton·Rongying Jin·E. W. Plummer·Jiandi Zhang
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Abstract

The dimensionality of the electronic and magnetic structure of a given material is generally predetermined by its crystal structure. Here, using elastic and inelastic neutron scattering combined with magnetization measurements, we find unusual magnetic behavior in three-dimensional (3D) Ba2CoO4. In spite of isolated CoO4 tetrahedra, the system exhibits a 3D noncollinear antiferromagnetic order in the ground state with an anomalously large Curie-Weiss temperature of 110 K compared to TN = 26 K. More unexpectedly, spin dynamics displays quasi-2D spin wave dispersion with an unusually large spin gap, and 1D magnetoelastic coupling. Our results indicate that Ba2CoO4 is a unique system for exploring the interplay between isolated polyhedra, low-dimensional magnetism, and novel spin states in oxides.

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Qiang Zhang, Guixin Cao, Feng Ye, Huibo Cao, Masaaki Matsuda, D. A. Tennant, Songxue Chi, S. E. Nagler, W. A. Shelton, Rongying Jin, E. W. Plummer, Jiandi Zhang. 2019-03-06. Anomalous Magnetic Behavior in Ba2CoO4 with Isolated CoO4 Tetrahedra. https://arxiv.org/abs/1903.02490

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