First-Principles Investigation of Electronic and Mechanical Properties of Nb-Doped MgO Ceramics

Abstract

Magnesium oxide (MgO) is widely studied for high-temperature and insulating applications. In this study, first-principles density functional theory (DFT) calculations were employed to evaluate the structural, electronic, and mechanical properties of Nb-doped MgO. The results showed that Nb incorporation slightly expanded the lattice and introduced donor states close to the conduction band, effectively reducing the band gap from 7.2 eV (pristine) to 6.3 eV. Elastic modulus and hardness calculations indicated enhanced mechanical strength due to strong Nb–O bonding. Charge density distribution confirmed significant orbital hybridization between Nb 4d and O 2p states. These findings suggest that Nb-doped MgO ceramics exhibit improved electronic conductivity while retaining robust mechanical stability, making them promising candidates for insulating layers in microelectronics and thermal barrier coatings.