ON THE OPTIMIZATION OF THE LASER ABLATION PROCESS FOR THE DEPOSITION OF YBA2CU3O7-DELTA THIN-FILMS

Pulsed-laser ablation is widely used to produce thin films of the YBa2Cu3O7-delta-superconductor. The technique consists of a number of variables which would be expected to influence film growth, it is therefore important to understand what effect the changing of these parameters will have, in order to optimize the growth process. Variation of some of the laser parameters has been shown to affect the morphology of the deposited films during the early stages of growth. For example, the growth rate was found to affect the microstructure of the film. At high growth-rates (approximately-1.5 nm/s), a mixture of c-axis and a- or b-axis oriented grains were formed, while at lower growth-rates ( <0.3 nm/s), the film was oriented exclusively with the c-axis perpendicular to the interface plane.