Pb(Zr0.53Ti0.47)O3 (PZT) films have been fabricated on stainless steel substrates by a Polyvinylpirrolidone (PVP) modified sol-gel route. The single layer of about 0.26 μm was achieved by using the PVP-modified PZT sol, and Crack-free PZT films with thickness of up to 2.37 μm were fabricated by repeating the deposition process. The variations in crystallite orientation, microstructure, dielectric and ferroelectric properties of PZT films were investigated as a function of film thickness. Our results indicate that PZT films prepared on stainless steel substrates maintain good dielectric and ferroelectric properties.

Polymer assisted deposition (PAD) has been reported as a novel CSD approach for thin film growth with improved homogeneity and long stability by forming a metal polymer species. It also offers the interesting possibility of having a library of PAD solutions for each precursor metal and obtaining the required composition by simple mixing. Another potential advantage is the increase in thickness since mechanical stresses are expected to be alleviated during shrinkage in the metalorganic decomposition by the metal-polymer network.

Cerium oxide films on YSZ single crystals were grown from water-based solutions containing cerium nitrate, polyethyleneimine and complexing EDTA, in order to explore the benefits of using the PAD approach for growing buffer layers in coated conductors. An ultrafiltration step was performed to remove the non-coordinated species in solution. The degree of purification and efficiency in the cerium recovery was investigated by different techniques. TGA-DTA analysis was used to provide guidance to the best thermal profiles in different atmospheres and specially to diminish the adverse effects of exothermic events during decomposition. Microstructural evolution was tracked by AFM and TEM, while epitaxial fraction was followed by X-ray diffraction. The results show the high importance of choosing the proper atmosphere and the need for tuning of heating ramps to obtain dense, flat and epitaxial ceria films by PAD.

Thermal analysis techniques are routinely applied to characterize the thermal behavior of metal organic precursors used for oxide film preparation. Since the mass of films is very low, researchers do their thermal analyses on powders and consider that the results are representative of films. We will show here that, in general, this assumption is not true. Several examples involving precursors of YBa2Cu3O7-x (Ba and Y trifluoroacetates and Ba propionate) will serve to appreciate that films can behave very differently than powders due to their enhanced heat and mass transport paths. Ultimately, we will demonstrate that, in some cases, relying on powders thermal analysis may lead to erroneous conclusions.

Electrochemical deposition was used to fabricate polycrystalline ZnO thin films in solutions containing zinc nitrate and hexamethylenetetramine. All samples showed intense UV photoluminescence (PL) near the band edge in addition to weak broad bands due to defects. When the source solution was slightly doped with Mg2+ ions, the defect induced emission was significantly suppressed while the UV peak position and intensity remained the same. Auger electron spectroscopy revealed no Mg contents in the films within the detection limit. A possible growth mechanism was proposed, based on the chemical reactivity of Mg and Zn, to interpret the observed PL data, which is supported by samples grown in Ca-doped solutions.

We report the synthesis of polycrystalline films of La1-xCaxMnO3 in Si (111) by Polymer Assisted Deposition (PAD). An aqueous solution polyethyleneimine (PEI) and different metal ions stabilized with EDTA, was spin coated on hydrophilized Si substrates and subsequently annealed under different atmospheres. Homogeneous, dense polycrystalline films are obtained at optimized conditions of 950 ºC under flowing O2. The morphology and magnetic properties of the samples are compared with films obtained by Pulsed Laser Deposition.

Water-soluble Fe3O4@ZnO composite nanoparticles (NPs) were synthesized using a polyol route. The effects of the addition of the ZnO phase were evaluated by varying the Zn/Fe molar ratio in the 0.25-1.00 range as a function of the reaction time. X-ray diffractometry confirmed the formation of the magnetite and ZnO phases and suggested the possible formation of a composite structure. Also, using this method, pure magnetite and ZnO NPs were synthesized. The average crystallite sizes were estimated to 6.3 ± 0.3 nm and 8.6 ± 0.6 nm for magnetite and ZnO NPs, respectively. The samples were examined using transmission electron microscopy. Fourier transform infrared spectra indicated the presence of adsorbed species onto the solids surface, which may explain the good stability of the materials in water. Photoluminescence measurements at room temperature for pure ZnO nanoparticles exhibited the characteristic excitonic emission around 395 nm. Vibrating Sample Magnetometer measurements at room temperature evidenced the superparamagnetic behavior of magnetite nanocrystals, with a saturation magnetization of 60emu/g. The maximum magnetization ranged from 28 to 54emu/g for the composite NPs. Mössbauer spectroscopy measurements at room temperature showed evidence of evolving Fe-sites associated to superparamagnetic particles, as reflected on the coexistence of prominent doublet peaks and very weak sextet peaks.