Film orientation of re123 prepared by chemical solution deposition

We investigated processing temperature dependencies of the preferred orientation axis of REBa₂ Cu₃O_7-y (RE123; RE=Yb, Er, Y, Gd, Sm, Nd, Pr and La) films prepared on various substrates by chemical solution deposition (CSD) using metal naphthenates. In the case of RE = Er, Y, Gd and Sm prepared on SrTiO₃, a/b-axis oriented films were obtained in a region of low temperatures, whereas there is no such temperature region for RE=Yb, Nd, Pr and La films. On the other hand, RE123 films prepared on LaAlCh gives o/b-axis orientation in a region of low temperatures except for Ybl23 film. The (102) pole figures of these films give four high density points with four-fold symmetry, indicating that their axes are in-plane aligned. In order to confirm relationship between a/b-axs oriented growth and ionic radius of RE elements (R_i,RE), we prepared rare-earth mixed Ybi_xEr_xBa₂Cu₃O_7-y and Sm_1-xNd_xBa₂Cu₃O_7-y films. Orientation of these films changed critically at certain average RAKE'S.