Oxide-diluted magnetic semiconductors (O-DMS) have attracted a great deal of interest in recent years due to the possibility of inducing room temperature ferromagnetism. These materials are of particular interest for spintronic devices such as spin valves. This review describes the experimental status of the O-DMS including the recent results on ZnO- and TiO2-based systems.

Mixed-valence perovskite manganites (Re 1−x A x MnO 3 where Re=rare earth, A=alkaline earth) provide a unique opportunity to study the relationships between the structure and the magnetotransport properties due to an interplay among charge carriers, magnetic coupling, orbital ordering and structural distortion. This makes these compounds very exciting from both the basic research and from the technological view point. As the technology pursued with these materials requires film growth, extensive studies have been made on materials synthesis, structural and physical characterization and device fabrication. In this article, the results of the different experimental techniques and the effects of the deposition procedure of the manganite thin films are first reviewed. Second, the relation between the structural and the physical properties mentioned, and the influence of strains discussed. Finally, possible applications of manganite thin films for spin electronics are presented. *

2D electron systems (2DESs) in functional oxides are promising for applications, but their fabrication and use, essentially limited to SrTiO3 -based heterostructures, are hampered by the need for growing complex oxide overlayers thicker than 2 nm using evolved techniques. It is demonstrated that thermal deposition of a monolayer of an elementary reducing agent suffices to create 2DESs in numerous oxides.

An insulator-to-metal transition below 240 K is induced by applying a 7 T magnetic field in Pr0.5Ca0.5MnO3 thin films grown by the pulsed laser deposition technique on [100]-SrTiO3 substrates. This value of the melting magnetic field, much lower that the one required in bulk (∼20 T), is assumed to be an effect of the tensile stress. These results confirm the importance of the bandwidth in the control of the physical properties of this compound and open the route to get colossal magnetoresistive properties by using strain effects.

Epitaxial La 2 NiMnO 6 thin films have been grown on (001)-orientated SrTiO 3 using the pulsed laser deposition technique. The thin films samples are semiconducting and ferromagnetic with a Curie temperature close to 270 K, a coercive field of 920 Oe, and a saturation magnetization of 5 µ B per formula unit. Transmission electron microscopy, conducted at room temperature, reveals a majority phase having "I-centered" structure with a ≈ c ≈ a sub 2 and b ≈ 2a sub along with minority phase domains having a "P-type" structure (a sub being the lattice parameter of the cubic perovskite structure). A discussion on the absence of Ni/Mn long-range ordering, in light of recent literature on the ordered double-perovskite La 2 NiMnO 6 is presented.

We report on the synthesis of high-quality Co-doped ZnO thin films using the pulsed laser deposition technique on (0001)-Al 2 O 3 substrates performed in an oxidizing atmosphere, using Zn and Co metallic targets. We firstly optimized the growth of ZnO in order to obtain the less strained film. Highly crystallized Co:ZnO thin films are obtained by an alternative deposition from Zn and Co metal targets. This procedure allows an homogenous repartition of the Co in the ZnO wurzite structure which is confirmed by the linear dependance of the out-of-plane lattice parameter as a function of the Co dopant. In the case of 5% Co doped, the film exhibits ferromagnetism with a Curie temperature close to the room temperature.

Thin films of the charge-ordered (CO) compound Pr 0.5 Ca 0.5 MnO 3 have been deposited onto (100)-oriented SrTiO 3 substrates using the Pulsed Laser Deposition technique. Magnetization and transport properties are measured when the thickness of the film is varied. While the thinner films do not exhibit any temperature induced insulator-metal transition under an applied magnetic field up to 9T, for thickness larger than 1100Å a 5T magnetic field is sufficient to melt the CO state. For this latest film, we have measured the temperature-field phase diagram. Compared to the bulk material, it indicates that the robustness of the CO state in thin films is strongly depending on the strains and the thickness. We proposed an explanation based on the distortion of the cell of the film.

Using pulsed laser deposition (PLD), metastable perovskite YMnO3 films were grown from a hexagonal YMnO3 target. The stabilization of the metastable phase is a result of the structural similarity between it and the perovskite substrates. X-ray and electron diffraction confirm the films' epitaxial nature but evince that the orientation and residual strains depend on the substrate. The implication of these findings is that PLD is a simple synthetic approach to stabilizing new, more complex, metastable perovskites.