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.