Film orientation of RE123 prepared by chemical solution deposition

We investigated processing temperature dependencies of the preferred orientation axis of REBa2 Cu3O7-y (RE123; RE=Yb, Er, Y, Cd, 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 LaAlO3 gives a/b-axis orientation in a region of low temperatures except for Yb123 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-axis oriented growth and ionic radius of RE elements (R-i,R-RE), We prepared rare-earth mixed Yb1-xErxBa2Cu3O7-y and Sm1-xNdxBa2Cu3O7-y films. Orientation of these films changed critically at certain average R-i,R-RE's.