<i>Ab Initio</i> Study of the Phonon Frequency, Electrical and Thermal Properties of TiN

Abstract

With a motivation to understand microscopic aspects of TiN relevant to the electronic structure, phonon and thermal properties of transition metal nitride TiN superlattices, we determine its electronic structure, phonon spectra and thermal properties using first-principles calculations based on density functional theory with a generalized gradient approximation of the exchange correlation energy. We find that the electronic bands crossed by EF are half occupied, TiN has the ability of taking part in chemical reactions and also has the surface activity; A large gap in its phonon spectra, anomalies in the phonon dispersion of metallic TiN, manifested as dips in acoustic branches, but it do not contain soft modes in any direction; The specific heat (Cv) of TiN rises rapidly at low temperatures, the Cv values of the material, is identical to the Dulong-Petit value at high temperatures. Under the quasi-harmonic approximation (QHA), the thermal expansion, specific heat and bulk modulus B(T) are obtained, and the B(T) decreases along with the increase of temperature.