In-situ preparation of c-axis oriented Y-Ba-Cu-O and Bi-Sr-Ca-Cu-O films on Si-substrates by laser ablation

This paper describes superconducting Y-Ba-Cu-O and Bi-Sr-Ca-Cu-O films in-situ on Si-substrates by KrF excimer laser ablation. Substrate temperatures between 700 and 750 degrees C and an oxygen partial pressure of about 0.1 mbar are required during deposition in order to obtain completely c-axis oriented Y1Ba2Cu3OY films on Si, which exhibit superconductivity with an onset at 90 K and zero resistance at 78 K. Under these optimum conditions the occurrence of the c-axis orientation can be obtained on a variety of substrates, such as Si, SiO2, Al2O3, Zr-foil or even polycrystalline stainless steel. The orientational selection on these substrates originate from a preferred grain growth in c-direction. Furthermore, the same conditions have been applied to the growth of entirely c-axis oriented Bi2Sr2 Ca1Cu2O8and Bi2Sr2Ca2Cu3O10 films on Si