PRESSURE COEFFICIENT OF THE SUPERCONDUCTING TRANSITION-TEMPERATURE WITHIN THE VAN HOVE SCENARIO

Pressure coefficient(beta) of the superconducting transition temperatu re is studied within the van Hove scenario considering a realistic den sity of states for two-dimensional systems and taking into account the variations of the Debye frequency, carrier concentration (n), hopping integral, and the effective attractive interaction of the system with pressure (p). beta is large for underdoped systems and it decreases w ith doping. In the overdoped region beta may be positive or negative d epending on the value of delta n/delta p. The experimental data points of the hole-doped cuprates are found to fit reasonably well with the theoretical results.