DEPOSITION OF BARIUM POTASSIUM BISMUTH OXIDE (BKBO) THIN FILMS BY LASER ABLATION

High transition temperature barium potassium bismuth oxide (BKBO) thin films have been successfully deposited by the method of pulsed-laser ablation. The best results were obtained ablating from a potassium-rich single target in a pure argon background onto < 100 > SrTiO3 substrates. Films with superconducting onset and zero resistance temperatures of 28.5 and 27.5 K, respectively, were routinely obtained, with room-temperature resistivity as low as 250 mu Omega-cm. X-ray diffraction analysis showed the films were single crystal and epitaxially oriented in the < 100 > direction. X-ray rocking curves of the BKBO (200) reflection revealed a FWHM of similar to 0.7 degrees Delta theta and also indicated that the BKBO < 100 > lattice direction was misoriented with respect to that of the SrTiO3 substrate by 0.13 degrees.