Uniaxial pressure dependence of the superconducting critical temperature in RBa2Cu3O7-Î high-Tc oxides

Abstract

We have obtained the three uniaxial-pressure derivatives of the critical temperature, Tc, for GdBa2Cu3O7−δ from the hydrostatic pressure dependence measured on films of different crystalline orientations. The strain derivatives are found to be extremely anisotropic in the a-b plane, inducing a decrease (increase) of Tc when compressing across (along) the CuO chains. A comparison of the results in c-oriented RBa2Cu3O7−δ films and superlattices for various R and substrates reveals a nonmonotonic relation between the critical temperature and pressure.