Crystal Structures, Optical, and Magnetic Properties of Zn_3-xMn_xTeO₆

Abstract

The effects of Mn 2+ doping on the structural, optical and magnetic properties of the corundum-related oxide Zn 3 TeO 6 were investigated. Polycrystalline ceramic samples of the solid solution Zn 3-x Mn x TeO 6 (0<x≤2.0) were prepared by a solid-state reaction route. Phase diagram as a function of Mn concentration indicates monoclinic (C2/c) structure for x<1.0, disproportionated mixing of both monoclinic (C2/c) and rhombohedral (R-3) structure for 1.0≤x ≤1.6, and R-3 structure for x≥1.8. Moreover, when x=2.0, ZnMn 2 TeO 6 was formed, in which the bond length of Te-O and Mn/Zn-O increased, and the Mn/ZnO 6 octahedra became more distorted. Rietveld refinements of the crystal structures from the powder X-ray diffraction (XRD) data showed that the Zn/MnO 6 octahedra were highly distorted in R-3 phase. With the increase of Mn 2+ doping content, the solid solution Zn 3-x Mn x TeO 6 demonstrated not only the structure change from C2/c to R-3, but also the color evolution from light yellow to dark yellow. In optical absorption spectroscopy, with the increase of Mn 2+ doping concentration, the absorption at 400-550 nm was enhanced, and