Nonlinear I–V characteristics and proximity effects for PrBa2Cu3O7−δ/YBa2Cu3O7−δ bilayered structures grown on (001) YBa2Cu3O7−δ single crystal substrates

Abstract

We have observed superconductivity induced by proximity effects for 100 nm thick (001) PrBa2Cu3O7−δ films pseudomorphically grown on (001) YBa2Cu3O7−δ single crystal substrates by vertical four-probe measurements. The induced superconductivity disappeared around 28 K and was recovered at around 15 K. The 220 nm thick (001) PrBa2Cu3O7−δ/YBa2Cu3O7−δ bilayers show nonlinear I–V behavior with 0.2 mV built-in potential at low temperature below 50 K. The local maximum of the vertical resistance appears around 25 K.