OXYGEN-CONTENT AND DISORDER IN A-AXIS ORIENTED YBA2CU3O7-DELTA THIN-FILMS

Using results of Raman spectroscopy, it is shown that the transition temperature T(c) (R = 0) of a-axis oriented YBa2Cu3O7-delta thin films strongly depends on the disorder in the oxygen sublattice. Regardless of deposition temperature T(d), the films have an oxygen deficiency delta < 0.1. However, at low T(d), films show T(c) almost-equal-to 50 K and a significant disorder in the distribution of chain and/or apex oxygen atoms. Using a template growth procedure we show that, at a sufficiently high T(d), the oxygen disorder vanishes and T(c) > 80 K, although the crystalline disorder, measured by the width of the (200) x-ray rocking curve, is increasing with T(d).