First-principles study on the physical properties of a layered ZnO with hexagonal α-BN structure

• The layered ZnO is first studied in terms of optical, mechanical, and thermal properties using first-principles calculations.
• The layered ZnO exhibits a good infrared reflectance with a broad reststrahlen band covering the infrared band below 600 cm−1.
• The layered ZnO is predicted to be a material behaving in a brittle manner, with a microhardness ~3.6 times higher than that of the wurtzite ZnO.
• The layered ZnO has the thermal properties similar to those of wurtzite ZnO, but having a little higher Debye temperature above room temperature.

A layered ZnO with α-BN structure has been studied using first-principles calculations based on density functional theory. The physical properties of the layered ZnO are calculated in terms of dielectric function, infrared reflectance, elastic coefficients, modulus, hardness, and heat capacity. The layered ZnO exhibits a good infrared reflectance with a broad reststrahlen band covering the infrared band below 600 cm−1. The layered ZnO is predicted to be a material behaving in a brittle manner, with a microhardness ~3.6 times higher than that of the wurtzite ZnO. The temperature-dependent thermodynamic functions suggest that the layered ZnO has the thermal properties similar to those of wurtzite ZnO, but having a little higher Debye temperature above room temperature.