S/N-Heterostructure of BiSrCaCuO/BiSrCuO grown by halide CVD (BSCCO/BSCO grown by halide CVD)

Abstract S/N-heterostructures consisting of superconducting BiSrCaCuO and metallic BiSrCuO thin films were produced on (100) MgO substrates by halide CVD. Critical temperatures (Tc at zero resistance) and critical current densities (Jc) of the BiSrCaCuO films on MgO substrates were Tc = 75 to 80 K and Jc = 1 ∼ 106 A/cm2 at 60 K. The resistivity of the metallic BiSrCuO films was 0.7 to 1.5 ∼ 10−3 Ω-cm from 10 to 300 K. X-ray diffraction of the S/N-heterostructure gave two distinct diffraction patterns which originate from (100) BiSrCaCuO and BiSrCuO crystal. High-resolution transmission electron microscopy (HRTEM) images showed the interface between the BiSrCaCuO and BiSrCuO films to be atomically abrupt. Energy-dispersive x-ray spectroscopy (EDXS) depth profiles were also evaluated using TEM samples. No Ca atom interdiffusion was detected at the BiSrCaCuO and BiSrCuO film interface. The critical temperature of S/N-multilayer samples was about 75 K.