Prediction of superconductivity of Ta₂AlC: in situ Raman spectrometry and density functional investigations

Abstract

In this paper, in situ Raman spectra of Ta 2 AlC are measured in the temperature range of 80-500 K at ambient pressure. The frequencies of the Raman modes decrease with increasing temperature, which have been explained by the anharmonic and thermal expansion effects. The line-width of E 2g (ω 3 ) mode increases at elevated temperatures, which is found to be due to the anharmonic phonon-phonon scatterings. On the other hand, the line-widths of E 2g (ω 1 ) and A 1g (ω 4 ) modes decrease continuously with increasing temperature, which is explained by the electron-phonon couplings of these two phonon modes with the Ta 5d electrons. The electron-phonon coupling strengths are obtained both in experiments and density functional calculations. Finally, Ta 2 AlC is predicted to be a new superconductive MAX phase.

Recent advances in linear and non‐linear Raman spectroscopy. Part IX

“…Xiang and co‐workers used in‐situ Raman spectrometry and DFT to predict the superconductivity of Ta 2 AlC. The electron–phonon coupling strengths are obtained both in experiments and DFT calculations that contribute to the prediction that Ta 2 AlC is a new superconductive MAX phase …”

First-principle Study and Experiment on Temperature-dependent Substitution Process of Si in Ti3(Si,Al)C2 Solid Solution

“…[30,31] By analyzing electron-phonon coupling strengths obtained both in experiments and density functional calculations, it is predicted that Ta2AlC might be a new superconductive MAX phase. [32] Lane [33] investigated the thermal expansions and temperature-dependent crystal structures of Ti-Al-C phase diagram in the temperature range of 373-1373K and demonstrated that thermal expansions of Ti2AlC, Ti3AlC2 and Ti5Al2C3 were higher in the c direction in contrast with a direction. Lu [34] reported the substitution behavior of Si atoms in the Ti2AlC ceramics and calculated the formation energy of this process to be -0.37 eV.…”

WITHDRAWN: Temperature-influenced Substitution of Si in Ti3(Si,Al)C2  Solid Solution

“…First-principles calculations are valuable to predict the properties and behaviors of crystalline materials [8,9]. By analyzing electron-phonon coupling strengths obtained both in experiments and density functional calculations, it is predicted that Ta 2 AlC might be a new superconductive MAX phase [10].…”