Phase transitions and thermal expansion of Sr2–xBaxNiMoO6 and Sr2Ni1–yZnyMoO6 solid solutions

Abstract

Sr_2–xBa_xNiMoO₆ and Sr₂Ni_1–yZn_yMoO₆ mixed oxides with a double perovskite structure have been synthesized by pyrolyzing polymer–salt materials. The phase composition and structure of the samples have been determined at 298 K. The effect of temperature on the crystal structure of Sr_1.75Ba_0.25NiMoO₆, Ba₂NiMoO₆, and Sr₂Ni_1–yZn_yMoO₆ has been studied for the first time. The linear thermal expansion coefficients of Sr_1.75Ba_0.25NiMoO₆, Ba₂NiMoO₆, and Sr₂Ni_1–yZn_yMoO₆ have been determined at temperatures from 298 to 1163 K in air.