PRESSURE EFFECT IN HIGH-TEMPERATURE SUPERCONDUCTORS

The model of the pressure effect on the critical temperature T-c,in hi gh-temperature superconductors [II], earlier proposed by the present a uthor and consisting in the increase of the pair wave function overlap with increase in pressure p that in its manifestations is equivalent to an increase in doping, is compared with the recent experimental dat a [1-4]. By making this model more precise for inhomogeneous specimens , we obtained the doping region near the optimal one where the critica l temperature is independent of doping, and the pressure region where it is independent of pressure. It is shown that, as observed in [1,2], the dependence of dT(c)/dp on doping in HgBa2CuO4+delta after excludi ng the influence of the specimen's inhomogeneous structure is explaine d satisfactorily by the model of [11]. So the introduction in [1,2] of a term in T-c,proportional to p(2) is unnecessary. An analogous compa rison is made for YBa2Cu3O6+y.