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arXiv · 1908.06032

A case study of bilayered spin-$1/2$ square lattice compound [VO(HCOO)$_2\cdot$(H$_2$O)]

S. Guchhait·U. Arjun·P. K. Anjana·M. Sahoo·A. Thirumurugan·A. Madhi·Y. Skourski·B. Koo·J. Sichelschmidt·B. Schmidt·M. Baenitz·R. Nath
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Abstract

We present the synthesis and a detail investigation of structural and magnetic properties of polycrystalline [VO(HCOO)$_2\cdot$(H$_2$O)] by means of x-ray diffraction, magnetic susceptibility, high-field magnetization, heat capacity, and electron spin resonance measurements. It crystallizes in a orthorhombic structure with space group $Pcca$. It features distorted VO$_6$ octahedra connected via HCOO linker (formate anions) forming a two-dimensional square lattice network with a bilayered structure. Analysis of magnetic susceptibility, high field magnetization, and heat capacity data in terms of the frustrated square lattice model unambiguously establish quasi-two-dimensional nature of the compound with nearest neighbour interaction $J_1/k_{\rm B} \simeq 11.7$~K and next-nearest-neighbour interaction $J_2/k_{\rm B} \simeq 0.02$~K. It undergoes a N\'eel antiferromagnetic ordering at $T_{\rm N} \simeq 1.1$~K. The ratio $\theta_{\rm CW}/T_{\rm N} \simeq 10.9$ reflects excellent two-dimensionality of the spin-lattice in the compound. A strong in-plane anisotropy is inferred from the linear increase of $T_{\rm N}$ with magnetic field, consistent with the structural data.

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S. Guchhait, U. Arjun, P. K. Anjana, M. Sahoo, A. Thirumurugan, A. Madhi, Y. Skourski, B. Koo, J. Sichelschmidt, B. Schmidt, M. Baenitz, R. Nath. 2019-08-16. A case study of bilayered spin-$1/2$ square lattice compound [VO(HCOO)$_2\cdot$(H$_2$O)]. https://doi.org/10.1103/physrevmaterials.3.104409

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