Influences of microstructures on superconducting properties in (Hg,Re)-1212 thin films

Superconducting (Hg,Re)-1212 thin films were successfully grown on SrTiO3 ( STO), LaAlO3 (LAO) and (La,Sr)(2)A1TaO(6) (LSAT) substrates by a so-called two-step process. The films on STO, LAO and LSAT exhibited substantially di fferent transport J(c) values of 9.0 x 10(6), 2.2 x 10(6) and 3.6 x 10(6) A /cm(2) at 80 K in a self-field, respectively, while similar T-c values of 1 12-116 K were observed. The microstructures of these thin films were examin ed by means of a scanning electron microscope (SEM) and a transmission elec tron microscope (TEM). The films were found to have different structural fe atures and different types of defects. Based on the SEM and TEM investigati ons, the influences of the film microstructures on their superconducting pr operties are discussed. (C) 2001 Elsevier Science B.V. All rights reserved.