Studies of leakage current inhomogeneity of Pb(Zr, Ti)O-3/YBa2Cu3Ox heterostructures on a nanometer scale

In this paper we investigate probing leakage current inhomogeneity of Pb(Zr ,Ti)O-3 (PZT)/YBa2Cu3Ox heterostructures by conducting atomic force microsc opy. With this technique, the morphology of the leakage paths could be prob ed. By comparing the morphology and leakage current images, we observe incr eased leakage current at grain boundaries for a sample with a relative unif orm PZT layer. However, the leakage paths are inhomogeneous when the PZT la yer has thickness variations, which are caused by inter-diffusions during a nnealing. The inter-diffusion was detected by Rutherford backscattering spe ctrometry. (C) 1999 Elsevier Science B.V. All rights reserved.