Variation Of The Transition Temperature In Strained Epitaxial Y1-Xprxba2cu3o7 Ultrathin Layers

Ultrathin films of Y1-xPrxBa2Cu3O7 (x=0,0.2,0.3) were deposited on perovskite La1.95Sr0.05CuO4, Pr1.95Ce0.05CuO4, and PrxBa2Cu3O7 buffer layers for comparing the effects of epitaxial strain on the superconducting transition temperature (T-c). The resulting changes in T-c demonstrated that in-plane compressive strains improved the superconductivity. The T-c was higher for Y1-xPrxBa2Cu3O7 films grown on PrxBa2Cu3O7 than for films grown on Pr1.95Ce0.05CuO4, which indicates that the variation of T-c in perovskite superconductors is also attributable to factors other than strain, such as interlayer coupling, interlayer strain, and interface roughness.