Preparation of YBa/sub 2/Cu/sub 3/O/sub y/ thick films on Y/sub 2/BaCuO/sub 5/:CeO/sub 2/ substrates by a diffusion process

High density YBa/sub 2/Cu/sub 3/O/sub y/ thick films were prepared on Y/sub 2/BaCuO/sub 5/(211) substrates with CeO/sub 2/ additions by a surface diffusion process between Ba/sub 3/Cu/sub 5/O/sub y/ composite coating powder and a 211 substrate. It was found that small addition of CeO/sub 2/ from 0 to 0.5 wt% to the 211 substrate had a strong effect on the reaction between the Ba/sub 3/Cu/sub 5/O/sub y/ coating layer and the 211 substrate, which led to the crystallization of YBCO thick film grains without impurity phases such as CuO and unreacted Y/sub 2/O/sub 3/ particles along the grain boundaries. As CeO/sub 2/ additions were increased from 0 to 5 wt%, the density of 211 substrate increased up to 80-90% and the critical temperature and the critical current density of 123 thick films also increased.