Direct Measurement of Fusion Enthalpy of LaAlO3 and Comparison of Energetics of Melt, Glass, and Amorphous Thin Films

Abstract

Enthalpy of fusion and melting temperature of perovskite LaAlO3 were measured using thermal analysis method as 124 ± 10 kJ/mol at 2134 ± 10°C, providing a value of 52 ± 4 J·(mol·K)−1 for entropy of fusion. Crystallization enthalpy of amorphous LaAlO3 thin films was found to change from −24 to −17 kJ/mol with decrease in film thickness from 100 to 20 nm. Differences in energetics of amorphous LaAlO3 films and glass cannot be explained exclusively by surface energy contribution but must reflect differences in structure between films and glasses in this system.