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arXiv · 1808.02219

Frustrated Magnetism of Pharmacosiderite Comprising Tetrahedral Clusters Arranged in the Primitive Cubic Lattice

Ryutaro Okuma·Takeshi Yajima·Tatsuo Fujii·Mikio Takano·Zenji Hiroi
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Abstract

We show that pharmacosiderite is a novel cluster antiferromagnet comprising frustrated regular tetrahedra made of spin-5/2 Fe3+ ions that are arranged in the primitive cubic lattice. The connectivity of the tetrahedra and the inter-cluster interaction of 2.9 K, which is significantly large compared with the intra-cluster interaction of 10.6 K, gives a unique playground for frustration physics. An unconventional antiferromagnetic order is observed below TN ~ 6 K, which is accompanied by a weak ferromagnetic moment and a large fluctuation as evidenced by Mossbauer spectroscopy. A q = 0 magnetic order with the total S = 0 for the tetrahedral cluster is proposed based on the irreducible representation analysis, which may explain the origin of the weak ferromagnetism and fluctuation.

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Ryutaro Okuma, Takeshi Yajima, Tatsuo Fujii, Mikio Takano, Zenji Hiroi. 2018-08-07. Frustrated Magnetism of Pharmacosiderite Comprising Tetrahedral Clusters Arranged in the Primitive Cubic Lattice. https://doi.org/10.7566/jpsj.87.093702

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