The T c of LSMO films grown on STO-buffered Si substrates decreases faster than films directly grown on STO with decreasing film thickness. The LSMO/STO film with thickness of 55 nm shows T c at about 360 K, which is close to the bulk value, whereas T c LSMO film on STO-buffered Si film of similar thickness is reduced to 320 K. This difference is attributed to the strain and interfacial disorders in LSMO film on STO/Si. The film surface morphology is influenced by the film thickness. Oxygenation of LSMO films on STO-buffered Si affects the T c minimally but improved the overall magnetization of the films due to better oxygenation, which is also the case for postannealing the sample at elevated temperatures. The thermomagnetic history effects observed in LSMO films of STO-buffered Si indicate the presence of inhomogeneity, mostly at the interface, which influences the magnetic properties significantly.

We report on the magnetic properties of epitaxial La 0.7 Ba 0.3 MnO 3 and La 0.7 Sr 0.3 MnO 3 films on Si ͑100͒ and Si ͑111͒ substrates using SrTiO 3 template layer, which demonstrate magnetic and electrical properties at and above room temperature. The magnetization data show magnetic transition and magnetic hysteresis at and above room room temperature. The films show well-defined magnetic domains. The ferromagnetic resonance studies show anisotropic effects related to ferromagnetic properties of films. The smaller grain size of about 20 nm in manganite films on SrTiO 3 / Si may be one of the reasons to minimize the strain effect through strain relaxation at the interface between SrTiO 3 and manganites through the formation of three-dimensonal islands.

Lasley-Hunter, B.; Hunter, D.; Noginov, Maxim; Dadson, J.B.; Zhang, K.; Rakhimov, Rakhim R.; Pradhan, Aswini K.; Zhang, Jun; and Sellmyer, David J., "Ferromagnetic resonance studies in ZnMnO dilute ferromagnetic semiconductors" (2006). David Sellmyer Publications. 7.

We report on ferromagnetic properties of ZnMnO and Co:TiO2 films grown by pulsed laser deposition with varying growth conditions. We have demonstrated that ZnMnO films show ferromagnetic properties at room temperature. However, oxygen plays a dominant role in the occurrence of ferromagnetism. Introducing carriers into ZnMnO films did not improve the ferromagnetic properties. Our experimental results indicate that the mechanism for ferromagnetism lies, probably, within the perspective of charge transfer between Mn ions through oxygen. On the other hand, our experimental results suggest that the ferromagnetism in Co:TiO2 films is controlled by the presence of small metal Co2+ clusters in the rutile TiO2 matrix, which are mainly present at the interface and on the surface of the films.