37. The Structural Correlation and Mechanical Properties in Amorphous Hafnium Oxide Under Pressure

In this chapter, the classical molecular dynamics technique was used to investigate the atomistic structure of amorphous hafnium oxide (HfO₂) under pressure. The local atomic structure and the liquid-solid transition of HfO₂ were analyzed the pair radical distribution functions, bond angle distributions, coordination number and the void distribution. The simulation reveals that although the fractions of structural units HfO_x and OHf_y strongly change with the density, the partial bond angle distributions of these structural units are identical for all constructed models. This result has enabled us to establish a relationship between the bond angle distributions and the fractions of structural units. From deformation of samples, elastic moduli and Poisson ratio were determined. The Young’s modulus and yield stress increase with the increasing density. The strain hardening becomes more pronounced as the density increases.