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We introduce enhanced hybridization of Ti 3d-O 2p electronic states by applying an inhomogeneous electric field to a perovskite oxide, SrTiO3, which leads to lattice deformation through electrostriction and the converse flexoelectric effect. However, unlike most studies revealing lattice responses to dipolar polarization, the enhanced electronic hybridization introduced in SrTiO3 is not strong enough to compensate local repulsions and gives rise to the off-centered Ti displacement. This is consistent with the fact that SrTiO3 has a small vibronic coupling constant compared to other ferroelectric materials. In situ time-dependent X-ray diffraction studies reveal lattice relaxation. Band structures and electronic hybridization play important roles in lattice relaxation, which is different from the relaxation of metals where the carrier concentration may be dominant. Our results provide insight into the coupling behaviors between the lattice and electronic hybridization, considering both static and dynamic aspects. [ABSTRACT FROM AUTHOR]

The current-perpendicular-to-plane magnetoresistivity (CPP-MR)/ρc(B) is investigated in single crystal ruthenates Ca3(Ru1-xTix)2O7 (x=0.02). This material is naturally composed of ferromagnetic metallic bilayers (Ru,Ti)O2 separated by nonmagnetic insulating layers of Ca2O2, resulting in tunneling magnetoresistivity. Non-monotonic ρc(B) curves as well as the inverse spin valve effect are observed around the magnetic phase transition associating with the metal-to-insulator transition. A spin dependent tunneling model with alternate distribution of hard and soft magnetic layers [(Ru,Ti)O2] is proposed to explain the exotic CPP-MR behavior. This eccentric CPP-MR behavior highlights the strong spin-charge coupling in double-layered ruthenates and provides a potential material for spintronic devices. [ABSTRACT FROM AUTHOR]

The lattice strain distributions of epitaxial SrTiO3 films deposited on LaAlO3 were investigated by in situ x-ray diffraction at the temperature range of 25–300 K, grazing incident x-ray diffraction, and high resolution x-ray diffraction. The nearly linear temperature dependence of the out-of-plane lattice constant of SrTiO3 was observed in the measured temperature range. The depth distribution of the lattice strain at room temperature for SrTiO3 films includes the surface layer, strained layer, and interface layer. [ABSTRACT FROM AUTHOR]

The temperature dependence of strain relaxation in Al0.22Ga0.78N layers, with and without a Si3N4 surface passivation layer, was investigated at temperatures from room temperature to 813 K using high-resolution x-ray diffraction. A small strain relaxation occurs in the unpassivated Al0.22Ga0.78N layers at high temperature. After passivating, an additional in-plane tensile strain and an initial increase of the residual tensile strain with increasing temperature were observed in Al0.22Ga0.78N layers, and at higher temperatures the residual tensile strain only decreases slightly in the 100-nm-thick Al0.22Ga0.78N layer, but a pronounced strain relaxation occurs in the 50-nm-thick one. The degree of strain relaxation of the passivated 50-nm-thick Al0.22Ga0.78N layer increases by about 33%, which results in the two-dimensional electron gas concentration reduction of about 16% at the whole temperature range in our measurements. [ABSTRACT FROM AUTHOR]

The magnetic and electrical properties of crystalline Mn0.05Si0.95 films prepared by post-thermal treatment of the as-deposited amorphous Si-Mn (95 at.%-5 at.%) have been investigated. Both the temperature dependence and field dependence of magnetization were measured using superconducting quantum interference devices, and it has been indicated that the film materials are ferromagnetic with Curie temperature over 400 K. X-ray diffraction analysis revealed full crystallization of the films and the incorporation of Mn into the host crystalline Si lattice. Behavior of thermally activated conduction processes of the films has been evinced by electrical property measurement for the films. [ABSTRACT FROM AUTHOR]

The characteristics of novel reverse-biased waveguide phase modulators are reported. These devices, which use the translation of a depletion edge, have provided the highest efficiency figure of merit (56 °/Vmm) ever reported for a reverse-biased device. Furthermore, the speed of the device is only limited by the RC time constant. The investigated devices were GaAs/AlGaAs ridge waveguide modulators, a geometry which is well suited for integrated optoelectronics. [ABSTRACT FROM AUTHOR]

Silicon diffusion into AlxGa1-xAs (x=0–0.4) from a sputtered Si film is described. It is shown that both the diffusion rate and the surface concentration of Si decrease with increasing Al mole fraction. The diffusion behavior of Si in AlxGa1-xAs is discussed in terms of the binding energy of the Al–As bond and mixed crystal disorder. [ABSTRACT FROM AUTHOR]

We introduce enhanced hybridization of Ti 3d-O 2p electronic states by applying an inhomogeneous electric field to a perovskite oxide, SrTiO3, which leads to lattice deformation through electrostriction and the converse flexoelectric effect. However, unlike most studies revealing lattice responses to dipolar polarization, the enhanced electronic hybridization introduced in SrTiO3 is not strong enough to compensate local repulsions and gives rise to the off-centered Ti displacement. This is consistent with the fact that SrTiO3 has a small vibronic coupling constant compared to other ferroelectric materials. In situ time-dependent X-ray diffraction studies reveal lattice relaxation. Band structures and electronic hybridization play important roles in lattice relaxation, which is different from the relaxation of metals where the carrier concentration may be dominant. Our results provide insight into the coupling behaviors between the lattice and electronic hybridization, considering both static and dynamic aspects. [ABSTRACT FROM AUTHOR]