MOLECULAR-BEAM EPITAXY FABRICATION OF SRTIO3 AND BI2SR2CACU2O8 HETEROSTRUCTURES USING A NOVEL REFLECTION HIGH-ENERGY ELECTRON-DIFFRACTION MONITORING TECHNIQUE

SrTiO3 and Bi2Sr2CaCu2O8 layered structures were continuously grown by the molecular beam epitaxy technique with in situ reflection high-energy electron diffraction (RHEED). By using a new RHEED picture subtraction technique, we could display intensity changes due to only the topmost layer. This method allows us to sensitively detect roughness on the atomic scale and excess phase formation. The SrTiO3 layer could be grown by sequential shuttering as well as coevaporation. A heterostructure with a 60 angstrom Bi2Sr2CaCu2O8 film had a superconducting transition temperature of 53 K.