Structural, electronic, and dielectric properties of amorphous ZrO2 from ab initio molecular dynamics

Realistic models of amorphous ZrO2 are generated in a “melt-and-quench” fashion using ab initio molecular dynamics in a plane-wave pseudopotential formulation of density-functional theory. The structural properties of the resulting amorphous models are analyzed, with special attention to coordination statistics. The vibrational and dielectric properties of one of these models are then investigated from first principles using linearresponse methods. The electronic dielectric constant and Born effective charges are found to be very similar to those of the crystalline phases. Encouragingly, the predicted total static dielectric constant is ,22, comparable to that of the monoclinic phase. This work is motivated by the search for improved gate dielectric materials for sub-0.1-mm complementary metal oxide semiconductor technology, and may also have implications for HfO2 and for silicates of ZrO2 and HfO2.