Ab Initio Study of the Structural and Mechanical Properties of Hf-Si-N
The structural and elastic properties of HfN and Hf-Si-N have been studied, using first principles calculations based on the density functional theory. These calculations provide the lattice parameter, cohesive energy and elastic constants of fcc (NaCl)-HfN, the N-deficient Hf-Si-N and the Hf-deficient Hf-Si-N solution phase. In order to study the relative stability, binding energy of all configurations has been calculated. The results showed that it was difficult to add a Si atom into the center of the HfN cell because the cohesive energy decreased. However, if an Hf atom or an N atom was missing in the HfN, a silicon atom was possible to occupy the vacant site and form the Hf-Si-N substitutional solid solution. Moreover, the bulk modulus, shear modulus and elastic modulus increased accordingly, the mechanical properties were improved.
Liangchi Zhang, Chunliang Zhang and Tielin Shi
X. Tan et al., "Ab Initio Study of the Structural and Mechanical Properties of Hf-Si-N", Advanced Materials Research, Vols. 139-141, pp. 22-25, 2010