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The dielectric response (permittivity and losses) of epitaxial CoFe2O4–BaTiO3 thin film nanocomposites deposited under different conditions has been measured. Exhaustive microstructural analyses have allowed tracking the evolution of structure and morphology as a function of thickness, deposition temperature and rate. It is found that the dielectric permittivity of the nanocomposite increases with the grain size of the BaTiO3 matrix and when reducing its unit cell volume, while losses are quite insensitive to changes in morphology and crystal structure of the ferroelectric phase. We analyze the consequences of these results in view of the functional optimization of nanocomposites. [ABSTRACT FROM AUTHOR]

The dielectric response of epitaxial Co[Fe.sub.2][O.sub.4]-BaTi[O.sub.3] thin film nanocomposites deposited under different conditions is measured. The studies have shown that the dielectric permittivity of the nanocomposite has increased with the grain size of the BaTi[O.sub.3] matrix and when reducing its unit cell volume, while losses are quite insensitive to changes in morphology and crystal structure of the ferroelectric phase.

Material selective sensitive of a magneto-optical polar Kerr effect to magnetic contributions from different inclusions in self-organized nanostructures is described. Magneto-optic selective sensitivity is explained as an effect of different complex diagonal and off-diagonal permittivity tensor elements of two materials.

The growth of self-assembled (0.65)BiFe[O.sub.3]-(0.35)Co[Fe.sub.2][O.sub.4] (BFO-CFO) nanostructures on SrTi[O.sub.3] (STO) substrates with different orientations and the effect of growth temperature on the crystal phases and their strain are studied. The studies have shown that interfacial stress has dominated the elastic properties of CFO crystallites and might play a fundamental on the interface magnetoelectric coupling in these nanocomposites.

A report on the magneto-optical measurements of an epitaxial SrRuO3 film grown on SrTiO3 (0 0 1), which previously was determined to be single domain oriented by x-ray diffraction and Raman spectroscopy techniques, is presented. The experiments performed reveal a large Kerr rotation that reaches a maximum value of about 0.5 degrees at low temperature.

Material selective sensitivity of a magneto-optical polar Kerr effect to magnetic contributions from different inclusions in self-organized magnetic nanostructures is presented. The method is supported by modeling of the magneto-optic response based on the effective medium approximation and by hysteresis loop measurement of the multiferroic BiFeO3–CoFe2O4 self-assembled nanostructure. Magneto-optic selective sensitivity is demonstrated and explained as an effect of different complex diagonal and off-diagonal permittivity tensor elements of two materials. [ABSTRACT FROM AUTHOR]

Self-assembled (0.65)BiFeO3–(0.35)CoFe2O4 (BFO-CFO) nanostructures were deposited on SrTiO3 (001) and (111) substrates by pulsed laser deposition at various temperatures from 500 to 800 °C. The crystal phases and the lattice strain for the two different substrate orientations have been determined and compared. The films grow epitaxial on both substrates but separation of the spinel and perovskite crystallites, without parasitic phases, is only obtained for growth temperatures of around 600–650 °C. The BFO crystallites are out-of-plane expanded on STO(001), whereas they are almost relaxed on (111). In contrast, CFO crystallites grow out-of-plane compressed on both substrates. The asymmetric behavior of the cell parameters of CFO and BFO is discussed on the basis of the role of the epitaxial stress caused by the substrate and the spinel-perovskite interfacial stress. It is concluded that interfacial stress dominates the elastic properties of CFO crystallites and thus it may play a fundamental on the interface magnetoelectric coupling in these nanocomposites. [ABSTRACT FROM AUTHOR]

We report on the magneto-optical measurements of an epitaxial SrRuO3 film grown on SrTiO3 (0 0 1), which previously was determined to be single domain orientated by x-ray diffraction and Raman spectroscopy techniques. Our experiments reveal a large Kerr rotation, which reaches a maximum value of about 0.5° at low temperature. By measuring magnetic hysteresis loops at different temperatures, we determined the temperature dependence of the Kerr rotation in the polar configuration. Values of the anisotropic magnetoresistance ∼20% have been measured. These values are remarkably higher than those of other metallic oxides such as manganites. This striking difference can be attributed to the strong spin-orbit interaction of the Ru 4d ion in the SrRuO3 compound. [ABSTRACT FROM AUTHOR]

LaNiO3 (LNO) thin films of 14 nm and 35 nm thicknesses grown epitaxially on LaAlO3 (LAO) and (LaAlO3)0.3(Sr2TaAlO6)0.7 (LSAT) substrates are studied using High Resolution Transmission Electron Microscopy (HRTEM) and High Angle Annular Dark Field (HAADF) imaging. The strain state of the films is studied using Geometric Phase Analysis (GPA). Results show the successful in-plane adaptation of the films to the substrates, both in the compressive (LAO) and tensile (LSAT) cases. Through the systematic analysis of HRTEM superstructure contrast modulation along different crystal orientations, localized regions of the monoclinic LaNiO2.5 phase are detected in the 35 nm films. [ABSTRACT FROM AUTHOR]