ORIENTATION TEXTURE IN YBA2CU3O7-DELTA FILMS SYNTHESIZED FROM AMORPHOUS PRECURSORS

The metalorganic decomposition technique was utilized in the fabricati on of YBa2Cu3O7-delta films with preferred orientation on (100) MgO an d (100) SrTiO3 substrates. The processing parameters such as film thic kness, firing treatment, and substrate modifications were controlled t o obtain a high degree of three-dimensional preferred growth in the fi lms. Results indicate that three-dimensional film preferred growth dim inishes with increasing film thickness. Preferential growth in YBa2Cu3 O7-delta films is enhanced with increasing firing temperature and redu ced oxygen partial pressure due to enhanced atom mobility. Epitaxial g rowth of YBa2Cu3O7-delta films has been achieved on both lattice misma tched (MgO) and on lattice matched (SrTiO3) substrates. Epitaxial grow th is promoted by lattice matched substrates at lower film firing temp eratures. An attempt is made to understand the development of YBa2Cu3O 7-delta film preferential growth via the epitaxial grain growth mechan ism.