MICROWAVE SURFACE RESISTANCE OF EPITAXIAL YB2CU3O7-X FILMS

摘要

The microwave surface resistance R(s) at 10 GHz was measured for the epitaxial YBa2Cu3O7-x films deposited on a MgO (001) substrate by the sputtering method. These films were completely oriented with the c-axis normal to the surface and the in-plane alignments were YBa2Cu3O7-x [100] parallel to MgO [100] and YBa2Cu3O7-x [010] parallel to MgO [100], having a little or no fraction of misaligned grains or domains with large-angle boundaries. The R(s) values of the films correlated with the domain size more strongly than with the fraction of misorientation, implying that the domain boundaries themselves, even if they were not large-angle domain boundaries, lead to the increase of the surface resistance. The weak couplings between the domains are considered to be the main cause of the increase in the microwave surface resistance. [References: 17]