Structural, mechanical, electronic and optical properties of layered ternary nitrides SrZrN_2 and SrHfN_2: First-principles calculations

摘要

Using the first-principles density functional theory, we have studied the structural, elastic, mechanical, electronic and optical properties of the layered ternary nitrides SrZrN_2 and SrHfN_2. The calculated ground state properties of SrZrN_2 and SrHfN_2 are in agreement with the available experimental data. The independent elastic constants and mechanical properties have been calculated. Results show that SrZrN_2 and SrHfN_2 are all mechanically stable and brittle. SrZrN_2 is a semiconductor with an indirect gap of 0.993 eV and that for SrHfN_2 is 1.139 eV. Moreover, the complex dielectric function, refractive index, extinction coefficient, reflectivity, absorption coefficient, loss function and optical conductivity of two compounds have been calculated.