Prediction of phase change in pseudobinary transition metal aluminum nitrides by band parameters method

The phase change of transition metal aluminum nitride (T1−xAlxN; T: transition metal) was predicted by the band parameters method based on the concept of a localized electron theory. Two band parameters were semiempirically constructed from pseudopotential radii and valence. Critical content of AlN for B1/B4 phase change was predicted by using the structural map constructed from two band parameters. These predicted contents of AlN showed good agreement with the experimentally determined values in three pseudobinary nitrides. Subsequently, the increase of bulk modulus was indicated in the B1-type T1−xAlxN pseudobinary nitride by calculating from the power functional formula of interatomic distance under the assumption that the AlN bond has no sp-bonded character in the B1-type T1−xAlxN pseudobinary nitride. It was indicated that the increase of the bulk modulus is an important factor to improve the hardness of T1−xAlxN pseudobinary nitride films.