Study of the anomalous behavior of the a-HFO2 refractive index with increasing Si doping by quantum molecular dynamics simulation

Abstract

This paper provides an atomistic exploration of amorphous composite HfO2-SiO2 oxides to explain the experimentally observed anomalous behavior of the refractive index with increasing Si content. We use an approach to obtain amorphous states of high-temperature oxides by melting–quenching the initial HfO2 crystal containing various amounts of Si impurities. The calculations are carried out by quantum molecular dynamics. The coordination numbers of Hf, Si, and O atoms are studied at various doping levels. The change in the atomic structure of a-HfO2 depending on the doping level qualitatively explains the anomalous behavior of the refractive index.