Superconducting thin films of Y-Ba-Cu oxide have been prepared on yttria-stabilized zirconia substrates using metal trifluoroacetate spin-on precursors. The films exhibit an extremely sharp resistive transition with zero resistance at temperatures as high as 94 K. The superconducting phase is formed by a three-step process: (a) decomposition of the spun-on trifluoroacetate film to the fluorides, (b) conversion of the fluorides to oxides by reacting with water vapor, and (c) annealing followed by slow cooling in oxygen. The properties of the films depend on the amount of conversion of the fluorides by reaction with water. Films which show the presence of some unreacted barium fluoride have strong c-axis normal preferred orientation, with a sharp resistive transition. When all the barium fluoride is converted, the film is more randomly oriented and exhibits a broader transition to zero resistance.

Bubble domains have been observed in five composite garnet structures consisting of two epitaxial magnetic layers separated by a layer of nonmagnetic garnet. The static and ``ordering'' properties of the domains are described and the arrangement of the overlying domains is discussed as a function of bias field. It is shown qualitatively that the strength of the magnetostatic interaction between the two magnetic layers can be changed considerably by varying the relative film thicknesses in the composites.

We demonstrate that lanthanum gallate (LaGaO3) has considerable potential as an electronic substrate material for high-temperature superconducting films. It provides a good lattice and thermal expansion match to YBa2Cu3O7−x, can be grown in large crystal sizes, is compatible with high-temperature film processing, and has a reasonably low dielectric constant (ε≂25) and low dielectric losses. Epitaxial YBa2Cu3O7−x films grown on LaGaO3 single-crystal substrates by three techniques have zero resistance between 87 and 91 K.

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Crystallographic parameters, Curie points, and freezing temperatures are presented for a series of A'A,"+Nb50i5 compositions with tungsten bronze-related structures, where A'=Na, K, or Rb, and A2+=Sr or Ba. Results are also reported for bronze solid solutions in the systems KNb0,-PbNb,O,, K (Sr-Ba) zNb60i5, K( Ba-Pb) zNb50i6, K(Sr-Pb)zNb6015, and (KSrz-KzLa)Nb5O15. On the basis of these data, an empirical relation is shown between the ferroelectric transition temperature, Tc, and axial ratio V-13 co/ao. The T o vs V% c 0 / a curve for compositions with polar axes perpendicular to [OOll has a negative slope, whereas that for compositions with polar axes parallel to 100lj has a positive slope of about the same magnitude. These results are compared with measurements of the temperature dependence of co/uo for KSrPbNbsOi, and KBa,Nb,O,,; the latter is discussed in terms of the Devonshire free energy theory.