Pressure‐Tuned Mechanical Behaviors and Thermal Properties of a New M ₂ AB Phase V ₂ PB: Density Functional Theory Investigation

Boron‐containing MAX phases represent a promising yet relatively underexplored class of materials with potential for high‐temperature and structural applications. In this study, we investigate V 2 PB, a newly proposed M 2 AB‐phase compound, to address inconsistencies in reported thermal properties and assess its behavior under pressure. Using first‐principles calculations based on density functional theory, we systematically examine its structural stability, electronic structure, mechanical strength, and thermal transport properties under pressures up to 50 GPa. The results reveal that V 2 PB remains thermodynamically and dynamically stable up to 20 GPa, beyond which structural instabilities emerge. The material demonstrates exceptional mechanical performance, with a bulk modulus of 155.4 GPa, shear modulus of 117.7 GPa, Young's modulus of 281.9 GPa, and a theoretical hardness of 31.25 GPa—indicating high stiffness and deformation resistance comparable to structural ceramics. Although its relatively high minimum thermal conductivity (1.56 W·m −1 ·K −1 ) limits its suitability for thermal barrier coating applications, the combination of superior mechanical robustness, a high Debye temperature of 761 K, and an elevated melting point of 1860 K highlights V 2 PB's excellent thermal stability and supports its potential for high‐temperature structural and heat dissipation applications.