Direct measurement of fusion enthalpy of LaAlO ₃ and comparison of energetics of melt, glass, and amorphous thin films

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.