First-principles study on the phase transition, elastic properties and electronic structure of Pt3Al alloys under high pressure

Theoretical study of the elastic and thermodynamic properties of Pt_{3}Al with the L1_{2} structure under high pressure

“…Our results show that the formation enthalpies of cubic structure are lower than that of tetragonal structure below 100 GPa. This means that cubic Pt 3 Al is stable under high pressure which is consistent with the result of Liu [11]. To obtain equilibrium structural parameters, the atom position and structure of Pt 3 Al were optimized.…”

“…In addition, Yan et al have researched the phase transition and formation enthalpies of Pt 3 Al under high pressure. The results show that the cubic structure is stable compared to the tetragonal structure up to the pressure of 100 GPa and has excellent resistance to volume deformation under high pressure [11]. Despite the above investigations, there have been no systemic experimental or theoretical reports on the elastic and thermodynamic properties of L1 2 phase Pt 3 Al alloys under high pressure.…”

Iridium concentration driving the mechanical properties of iridium–aluminum compounds

“…Some reports have shown that the operating temperature of IreAl compounds at oxidation environment is above 1800 C, which is much higher than the existing Ni-based alloys [6e8]. The first-principles calculations further found that the calculated shear modulus and Young's modulus of IrAl is 178 GPa and 423 GPa, respectively [9], which are much bigger than that of PteAl alloys [10]. Chao Jiang et al pointed out that although alloying of W in g-Ir 3 (Al, W) weakens the ductility at room temperature, it significantly enhances its strength [11].…”

Electronic and Mechanical Properties of Tetragonal Nb2Al Under High Pressure: First-Principles Calculations

“…Hou et al [22] calculated the structural, elastic, thermodynamic, and electronic properties of L1 2 -ordered Ni 3 Al, showing that it was mechanically stable and had no structural phase transition up to 50 GPa. Liu et al [23] studied the phase transition and electronic structure of Pt 3 Al alloys, showing that there was a phase transition from tetragonal phase to cubic phase at 60 GPa and the hybridization between Pt and Al atoms were enhanced under pressure. If the elastic constants satisfy the Born stability criterion [24][25][26] (the criterion for a stable crystal requires a positive determinant for the crystal's symmetric matrix), the crystal structure is mechanically stable.…”