S/N-Heterostructure of BiSrCaCuO/BiSrCuO Grown by Halide CVD

Abstract Thin film S/N heterostructures of superconducting BiSrCaCuO and metallic BiSrCuO with a good surface morphology, crystallinity, and superconducting properties were formed on (100) MgO substrates by halide CVD. Critical temperatures (zero resistance at Tc) and critical current densities (Jc) of the BiSrCaCuO films on MgO substrate were Tc = 75 to 80 K and Jc = 1×10 6 A/cm 2 at 60 K. Electrical resistance of the metallic BiSrCuO films was 1 to 2 ×10 −3 ohm-cm from 10 to 300 K. High resolution transmission electron microscopy (HRTEM) images showed the interface between the BiSrCaCuO and BiSrCuO films to be atomically very abrupt. The critical temperatures of S/N-multilayer samples was about 75 K. In this work, we fabricated S/N-heterostructures of bismuth-compound crystals grown by halide CVD and studied the film quality and superconducting properties.