Effect of Stress on the Superconductive Transition Temperature of Strontium Titanate

The superconductive transition temperatures $T_c$ of single-crystal specimens of reduced strontium titanate have been measured as functions of hydrostatic and uniaxial compressional stresses up to 1.5 kbar. The prominent features of the experimental results are a large, nonlinear, hydrostatic-pressure effect and an anisotropic uniaxial stress effect. The relative decrease of transition temperature with pressure $\frac{\Delta \left(\ln T_c\right)}{\Delta p}$ is about an order of magnitude larger than that seen in metallic superconductors.