Pressure dependence of the superconducting properties of the rare-earth-based Heusler compounds ReRh2Sn (Re=Sc, Y and Lu)

Abstract

This study employed density functional theory (DFT) within the generalized gradient approximation (GGA) to investigate the structural, electronic, vibrational and superconductivity properties of full-Heusler compounds ReRh₂Sn (Re=Sc, Y and Lu) under pressure ranging from 0 to 10 GPa. The analysis of the results reveals that the studied compounds exhibit metallic behavior with robust dynamic stability under pressures up to 10 GPa. The superconducting properties were evaluated using the isotropic Eliashberg function, and the obtained values of the superconducting critical temperature T${}_{\text{C}}$ and electron–phonon coupling constant ${\lambda }_{ep}$ indicate that ReRh₂Sn compounds are weak to moderate coupled superconductors. Among the studied compounds, YRh₂Sn exhibits the highest superconducting critical temperature T${}_{\text{C}}$. As the pressure increases from 0 to 10 GPa, the electron–phonon coupling constant (${\lambda }_{ep}$) decreases. This reduction, along with a decrease in the density of states at the Fermi level, leads to a decline in the superconducting critical temperature. Additionally, we report the thermodynamic parameters such as the superconducting gap $\Delta$, the Sommerfeld constant ($\gamma$), the specific heat jump at T${}_{\text{C}}$ and the Ginzburg–Landau parameter(${\kappa }_{GL}$). The results demonstrate that these parameters decrease with increasing pressure for ScRh₂Sn and YRh₂Sn. However, between 0 to 5 GPa, the parameters decrease, while they decrease between 5 GPa to 10 GPa.