Effect of manganese doping on vibrational and physical properties of ZrTe 3 O 8

Abstract

The powder sample of xMnO2–(1−x) ZrTe3O8 (x = 7%) was prepared by the conventional solid state reaction method. X-ray diffraction showed that the compound crystallized at room temperature in the cubic fluorite structure (in a cubic unit-cell Ia3¯ as MTe3O8-type framework) with lattice parameter a = 11.3298(2) Ǻ. The structure was built up of TeO4E (E = Electronic lone pair of Te(IV)) disphnoids and regular ZrO6 octahedra. The crystal structure cohesion was ensured via TeO(2)Zr and TeO(1)Te bridges. The Raman spectrum was dominated by a stronger band at 858 cm−1, characteristic of TeO(2)Zr bridges asymmetric stretching vibration. Thus, the TeO(2) and Zr(Mn)O(2) bonds are chemically inequivalent and then the TeO(2)Zr bridges are chemically asymmetric. Magnetization measurements versus temperature in an applied magnetic field of 0.05 T were determined. The doping of Zr by Mn induces a ferro-paramagnetic transition at T = 18.5 K. The complex impedance of the xMnO2-(1−x) ZrTe3O8 (x = 7%) ceramics has been investigated in the temperature range 293–843 K and in the frequency range 100 Hz–1 MHz. Dielectric data were analyzed using complex permittivity (ε′), (ε″) and tan (δ) for the sample at various temperatures. The conductivity follows the Arrhenius relation.