HIGH QUALITY SmBa2Cu3O7-X THIN FILMS FOR MICROWAVE APPLICATIONS

Abstract

In this paper we report on the analysis of the surface properties of c-axis oriented, highly epitaxial SmBa 2 Cu 3 O 7-X thin films grown by high oxygen pressure d.c. sputtering technique on (100)k LaAlO 3 substrates. Structural and morphological characterizations of the samples were carried out by means of X-Ray diffraction and AFM analysis. The AFM images show a surface morphology with characteristic screw dislocations with roughness of 2-3 nm on 1 μ m 2 area. The superconducting properties indicate a critical temperature Tc(R=0)>90K and a critical current density Jc>1*106A/cm 2 at T=77K. Preliminary microwave measurements on meanderline microstrip resonators show surface residual resistances Rs<13μΩ a 1 GHz at T=4.2K .