Crystal growth and characterization of the magnetic properties of CuSb 2O 6

Abstract

CuSb 2O 6 crystallizes in a monoclinically distorted trirutile structure. Although the crystal structure indicates a nearly square planar Cu 2+ lattice, the spin system is quasi-one-dimensional (spin chains). In the paper crystal growth, twinning and magnetic properties of the compound are considered. CuSb 2O 6 single crystals of size up to 125 mm 3 were grown by chemical vapor transport with TeCl 4 as a transport agent. The crystals grew from gas phase in the tetragonal modification and transformed to the monoclinic modification upon cooling to room temperature. This results in twinning of the crystals. Uniaxial pressure treatment up to 30 MPa failed to detwin the crystals. The magnetic susceptibility of grown crystals shows a broad anomaly at ≈60 K indicating the onset of one-dimensional magnetic correlations. A sharp drop at T N =8.6(1) K marks a further transition to long-range antiferromagnetic (AF) ordering. The susceptibility can be well fitted to the linear uniform S= 1 2 Heisenberg AF model. Heat capacity measurements also demonstrate the transition to long-range magnetic order and the low dimensionality of CuSb 2O 6.