The Coefficients of Thermal Expansion of La2O3, TaVO5 and Ta16W18O94 Below Room Temperature

The coefficients of thermal expansion (CTE) of La2O3, TaVO5 and Ta16W18O94 were measured in the temperature range 150–300 K for space applications. Hot pressed La2O3 showed a positive CTE of 8.6 × 10−6 K−1. Sintered TaVO5 had a positive and extraordinarily large CTE (50 × 10−6 K−1), but the CTE was negative (−4.0 × 10−6 K−1) in the temperature range 340–380 K. The thermal expansion data suggest a reversible phase transformation near 260 K. The CTE of hot pressed Ta16W18O94 was −1.52 × 10−6 K−1. Sintered Ta16W18O94 showed slight hysteresis, but the CTE was about −1.0 × 10−6 K−1.