First principles investigation of the electronic, elastic and vibrational properties of tungsten disilicide

Interest in tungsten disilicide is growing due to its use as protective coatings and non-volatile memory devices but fundamental investigations on tungsten disilicide vibrational properties are lacking in literature. In particular, the phonon vibration modes have never been described. This paper presents a first-principles investigation of the vibrational properties of WSi2 crystals. The elastic and electronic properties are considered as well.First, the electron band structure is computed. Extra electronic levels for the valence electrons as compared to previously published results are found, highlighting the need for state-of-the-art DFT calculations. It is shown that the ionicity plays only a little role in the W–Si bonding. Instead, a strong degree of covalency is found.The elastic constants are computed in good agreement with the available experimental data. The complete phonon density of state as well as band structure are presented and all vibration modes are described. The phonon vibrations are also correlated to IR and Raman investigations available in the literature.

► Full electronic structure description. ► Elastic properties. ► Phonon band structure and DOS. ► Analysis of vibration modes.