Abstract
Nb2 SC and Nb2 AsC are among the identified superconducting MAX phases, both exhibiting a transition temperature Tc lower than 10 K. These compounds appear to belong to the conventional class of superconductors. By calculating the electron-phonon couplings of these materials, we have found that the predicted transition temperatures are approximately 6 K for Nb2 SC and 2 K for Nb2 AsC, closely matching the experimental findings. However, when subjected to pressure or strain, Nb2 SC and Nb2 AsC exhibit contrasting behaviors. While the transition temperature of Nb2 SC can be doubled by applying pressure up to 50 GPa, the transition temperature of Nb2 AsC significantly decreases under the same pressure. On the other hand, in the case of Nb2 AsC, a uniaxial tensile strain of approximately 2% along the c direction can enhance the compound's transition temperature by about 40%. These results show that with the right pressure or strain, it is possible to increase superconducting transition temperature in the Nb2 AC compounds.