Thermoelectric Properties of Double Perovskite (Sr, Ba)₂(Fe, Mn)(Mo, V)O₆

Abstract

Sr₂FeMo_1-xV_xO₆ (x=0-1.0), Sr_2-yBa_yFeMo_0.8V_0.2O₆ (y=0-1.0) and Sr_1.4Ba_0.6Fe_1-zMn_zMo_0.8V_0.2O₆ (z=0-1.0) samples were prepared by using a conventional ceramic method. The crystal structure, bulk density and resistivity of the samples were investigated. The thermoelectric properties of Sr_2-yBa_yFe_1-zMn_zMo_0.8V_0.2O₆ were examined. In the X-ray diffraction patterns of the samples sintered at 1200°C, the double perovskite phase was confirmed. Sr_1.4Ba_0.6FeMo_0.8V_0.2O₆ sample had the highest conductivity in Sr_2-yBa_yFe_1-zMn_zMo_0.8V_0.2O₆ samples. The Seebeck coefficients S of Sr_2-yBa_yFe_1-zMn_zMo_0.8V_0.2O₆ are negative for 100°C < T < 700°C so that these samples are n-type semiconductors. In particular, the power factor S²σ of Sr_2-yBa_yFe_1-zMn_zMo_0.8V_0.2O₆ samples increased with increasing Ba and Mn doping up to y=0.6 and z=0.2. The power factor S²σ of Sr_1.4Ba_0.6Fe_0.8Mn_0.2Mo_0.8V_0.2O₆ showed the largest value of 83.2 mW/K²m.