A theoretical investigation on the structural stability, superconductivity, and optical and thermodynamic properties of IrP under pressure

• Published in: RSC advances 2024-01, Vol.14 (2), p.1216-1228
• Main Authors: Sun, Xiao-Wei, Chen, Meng-Ru, Dou, Xi-Long, Li, Ning, Wang, Tong, Song, Ting
• Format: Article
• ISSN: 2046-2069
• DOI: 10.1039/d3ra07464a

The potential applications of Ir 2 P are promising due to its desirable hardness, but its fundamental properties are still not fully understood. In this study, we present a systematic investigation of Ir 2 P's structural, electronic, superconducting, optical, and thermodynamic properties of Ir 2 P under pressure. Our calculations show that Ir 2 P has a Fm 3&cmb.macr; m structure at ambient pressure, which matches well with experimental data obtained from high-pressure synchrotron X-ray diffraction. As pressure increases, a transition from the Fm 3&cmb.macr; m to the I 4/ mmm phase occurs at 103.4 GPa. The electronic structure and electron-phonon coupling reveal that the Fm 3&cmb.macr; m and I 4/ mmm phases of Ir 2 P are superconducting materials with superconducting transition temperatures of 2.51 and 0.89 K at 0 and 200 GPa, respectively. The optical properties of Ir 2 P indicate that it has optical conductivity in the infrared, visible, and ultraviolet regions. Additionally, we observed that the reflectivity R ( ω ) of Ir 2 P is higher than 76% in the 25-35 eV energy range at different pressures, which suggests that it could be used as a reflective coating. We also explored the finite-temperature thermodynamic properties of Ir 2 P, including the Debye temperature, the first and second pressure derivatives of the isothermal bulk modulus, and the thermal expansion coefficient up to 2000 K using the quasi-harmonic Debye model. Our findings offer valuable insights for engineers to design better devices. We predicted that both the Fm 3&cmb.macr; m and I 4/ mmm phases of Ir 2 P exhibit superconductivity with T c of 2.51 and 0.89 K at 0 and 200 GPa, respectively. Both phases are identified as reflective coatings with reflectivity exceeding 76% in the 25-35 eV range.