Calculation of Phonon Vibrational Spectra Superconductivity of Calcium Dinitride by Theoretical Calculation

Abstract

By theoretical calculation, the crystal structure, stability, and electron-phonon interactions of calcium dinitride (CaN2) have been described, and CaN2 is predicted to be a superconducting material. The action mechanism of thermodynamics about CaN2 are induced through the Debye-Grüneisen model. The dispersion curves of CaN2 show large pseudo-gaps in the 400–1300 cm−1 range. The total of the electron-phonon coupling constants for CaN2 is given by λ = 0.37, with a corresponding estimated superconducting temperature of Tc ≈ 1 K. The estimated superconducting temperature of CaN2 rose to 28.8 K as the pressure increased to 10 GPa, and then decreased monotonically at higher pressures to almost zero at 50 GPa.