The physical properties and mechanical behavior of NbB2 at high pressure

In this study, niobium diboride (NbB₂) was investigated using synchrotron radiation X-ray diffraction in a diamond anvil cell to analyze their compressive behavior at room temperature. The volume of the NbB₂ was fitted to its corresponding highest pressures of 32.2 GPa without experiencing structural phase transitions, leading to the determination of bulk modulus of 389(7) GPa. Additionally, we further investigated the bulk modulus, band structure and density of states of NbB₂ to 35 GPa by density functional theory. The results yielded a bulk modulus of 285 GPa for NbB₂. Importantly, it was observed that NbB₂ demonstrates both metallic and non-magnetic properties throughout the pressure range. In addition, we studied the deviatoric stress of NbB₂ at high pressure using linewidth analysis method. It was found that NbB₂ can support a maximum differential stress of 14.2 GPa at the pressure of 17.3 GPa.