Amorphous ZrO2 from Ab-initio molecular dynamics: Structural, electronic and dielectric properties

摘要

Realistic models of amorphous ZrO2 are generated in a ``melt-and-quench''fashion using ab-initio molecular dynamics in a plane-wave pseudopotentialformulation of density-functional theory. The structural properties of theresulting amorphous models are analyzed, with special attention to coordinationstatistics. The vibrational and dielectric properties of one of these modelsare then investigated from first principles using linear-response methods. Theelectronic dielectric constant and Born effective charges are found to be verysimilar to those of the crystalline phases. Encouragingly, the predicted totalstatic dielectric constant is about 22, comparable to that of the monoclinicphase. This work is motivated by the search for improved gate dielectricmaterials for sub-0.1 micron CMOS technology, and may also have implicationsfor HfO2 and for silicates of ZrO2 and HfO2.