Synthesis of HfO2 from hafnium hydroxide hydrate

Abstract A comprehensive study of processes taking place during synthesis and subsequent thermal treatment of hafnium oxide was performed. Synthesis of HfO2 involves following stages: stepwise dehydration of hydrated hafnium hydroxide, crystallization of metastable tetragonal phase of HfO2 and subsequent irreversible transition to the stable monoclinic modification. Preliminary heat treatment lowered temperature of crystallization of HfO2 and resulted in changing process mechanism.