FABRICATION OF YBA2CU3O7-X-PRBA2CU3O7-Y HETEROSTRUCTURE BY USING A HOLLOW-CATHODE DISCHARGE SPUTTERING SYSTEM

A sputtering system using dc hollow cathode discharge was developed fo r the propose of high Tc superconducting devices. Using this system, a s-grown superconducting thin films of YBCO have been formed on MgO and SrTiO3 substrates. Influence of the sputtering conditions such as the substrate temperature and discharge gas pressure on the T(c) and latt ice parameter was investigated. It was found that superconducting film s on MgO with T(c.zero) higher than 87 K were routinely obtained at th e pressure of 820 mTorr (5%O2) and substrate temperature of 700-degree s-C during deposition. The a/b-axis and c-axis oriented YBCO-PBCO hete ro-structures were also successfully formed on MgO and SrTiO3 substrat es.