Thermal Expansion of Scheelite-Like Molybdate Powders and Ceramics

Resumo

Na_xSr_{1 – 2x}Nd_xMoO₄ (x = 0–0.5, Δx = 0.1) solid solutions with the scheelite structure have been synthesized for the first time and their crystallographic parameters have been determined as functions of composition and temperature. Their thermal expansion coefficients have been determined in the temperature range 25–1000°C: α_a = (12.9–14.9) × 10^–6 °C^–1 and α_c = (24.9–25.9) × 10^–6 °C^–1. Using spark plasma sintering at t_max ≈ 872–985°C and τ ≈ 650–750 s, we have prepared ceramics with relative densities in the range 97–99%.