<i>c</i>-axis tunneling in multilayers NdBa2Cu3O7−δ junctions with PrBa2Cu3O7−δ barriers

Abstract

This letter reports c-axis tunneling spectroscopy investigations of high quality junctions fabricated from c-axis oriented NdBa2Cu3O7−δ/PrBa2Cu3O7−δ/NdBa2Cu3O7−δ multilayers deposited by pulsed laser deposition. The conductance spectra as a function of temperature show a smooth crossover from tunneling to metallic junction behavior. A temperature dependent BCS-like gap giving 2Δ/kBTc=6 was observed. The current–voltage characteristics exhibit supercurrent and quasiparticle tunneling that is commonly observed for superconductor–insulator–superconductor junctions.