Atomic defects and dopants in ternary Z-phase transition-metal nitrides CrMN with M=V, Nb, Ta investigated with density functional theory

TL;DR

This study uses density functional theory to analyze atomic defects and dopants in ternary Z-phase transition-metal nitrides CrMN, exploring defect formation energies, environmental dependencies, and implications for experimental analysis and material growth.

Contribution

It provides a detailed theoretical investigation of defect formation and doping in CrMN Z-phase nitrides, linking thermodynamic conditions to defect energetics.

Findings

Defect formation energies vary with chemical environment.

Different growth scenarios influence defect stability.

Results aid in interpreting experimental atomic-scale analyses.

Abstract

A density functional theory study of atomic defects and dopants in ternary Z-phase transition-metal nitrides CrMN with M=V, Nb, or Ta is presented. Various defect formation energies of native point defects and of substitutional atoms of other metal elements which are abundant in the steel as well, are evaluated. The dependence thereof on the thermodynamic environment, i.e. the chemical conditions of a growing Z-phase precipitate, is studied and different growth scenarios are compared. The results obtained may help to relate results of experimental atomic-scale analysis, by atom probe tomography or transmission electron microscopy, to the theoretical modeling of the formation process of the Z phase from binary transition metal nitrides.