An investigation on solid state reactions in heat treated Au/Pd thin films for electrodes applications.

The interface between metals and oxides is particularly interesting. It has been the main topic of many research projects to illustrate that their properties are highly dependent on the structure of the interface. Poor adhesion between gold films and oxides is well known. On the basis of solid solution between the materials, the main effect of a Pd thin film as the adhesion layer between substrate and Au was investigated. Pure palladium and gold films were grown by electron beam evaporation sequentially on the SrTiO3 (001) single crystal substrates. After different annealing time (from 0.06 to 1.8 ks) at 500 degrees C, the growth sequence of the compositions between Au and Pd evolved as a results of the solid solution were investigated by means of X-ray photoelectron spectroscopy (XPS), X-ray diffraction. Meanwhile the surface morphology and the surface topography were examined respectively by scanning electron microscopy (SEM) and atomic force microscopy (AFM) observation. The effect of an intermediate Pd adhesion layer and its influence on the interfacial properties and morphology of the Au layer is investigated.

Second Harmonic Generation Response in Thermally reconstructed Multiferroic ß'- Gd2(MoO4)3 Thin Films.

Gd2(MoO4)3 (GMO) is a well-studied multiferroic material that exhibits full ferroelectric and ferroelastic behavior at room temperature. However, its difficult stabilization in thin films has prevented the study and exploitation of its multiferroic properties in different architectures. Here, we report on the study of GMO thin films deposited on Si(001) substrates by Pulsed Laser Deposition (PLD). The physicochemical properties of the films are discussed and studied. Results obtained by X-ray diffraction, X-ray photoelectron spectroscopy, high resolution transmission microscopy and second harmonic generation show that the orthorhombic (ß'-GMO) multiferroic phase can be stabilized and homogenized by post deposition thermal reconstruction. Finally, the reconstruction process takes place via a complex surface mechanism with a clear leaf-like behavior.