Abstract:
Doping superconductors are known to vary the superconducting transition temperature TC
depending on the degree of holes or electrons introduced in a system. In this study, we report how
pressure-induced hole doping influences the TC of GdBa2Cu3O7−x superconducting perovskite. The
study was carried out in the framework of density functional theory (DFT) using the Quantum
espresso code. Ultrasoft pseudopotential with generalized gradient approximation (GGA) functional
was used to calculate the ground state energy using the plane waves (PW). The stability criterion was
satisfied from the calculated elastic constants. The BCS theory and the Mc Millan’s equation was used
to calculate the TC of the material at different conditions of pressure. The underdoped regime where
the holes were less than those at optimal doping was found to be below 20 GPa of doping pressure.
Optimal doping where the material achieved the highest TC (max)∼20 GPa of the doping pressure.
Beyond the pressure of∼20 GPa was the over doping regime where a decrease in TC was recorded. The
highest calculated TC (max) was∼141.16 K. The results suggest that pressure of∼20 GPa gave rise to
the highest TC in the study.
