34 research outputs found

    Study of the photovoltaic effect in thin film barium titanate

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    The photoelectric effect in structures consisting of metal deposited barium titanate film silicon is described. A radio frequency sputtering technique is used to deposit ferroelectric barium titantate films on silicon and quartz. Film properties are measured and correlated with the photoelectric effect characteristics of the films. It was found that to obtain good quality pin hole free films, it is necessary to reduce the substrate temperature during the last part of the deposition. The switching ability of the device with internal applied voltage is improved when applied with a ferroelectric memory device

    Magnetoresistance devices Progress report

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    Investigating galvanomagnetic effects in developing higher magnetoresistance devices for low voltage high current switche

    Electron beam evaporated high mobility thin films of indium antimonide

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    Electron beam evaporation and recrystallization of InSb thin films yielding high Hall mobilitie

    A study of metal insulator semiconductor magnetoresistance, bulk, and surface properties of indium antimonide

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    Metal-insulator-magnetoresistance, bulk, and surface properties of indium antimonide compound semiconductor materia

    Microscopic Theory of Magnon-Drag Thermoelectric Transport in Ferromagnetic Metals

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    A theoretical study of the magnon-drag Peltier and Seebeck effects in ferromagnetic metals is presented. A magnon heat current is described perturbatively from the microscopic viewpoint with respect to electron--magnon interactions and the electric field. Then, the magnon-drag Peltier coefficient \Pi_\MAG is obtained as the ratio between the magnon heat current and the electric charge current. We show that \Pi_\MAG=C_\MAG T^{5/2} at a low temperature TT; that the coefficient C_\MAG is proportional to the spin polarization PP of the electric conductivity; and that P>0P>0 for C_\MAG<0, but P0P0. From experimental results for magnon-drag Peltier effects, we estimate that the strength of the electron--magnon interaction is about 0.3 eVâ‹…AËš3/2\cdot\AA^{3/2} for permalloy.Comment: 3 pages, 2 figures, accepted for publication in Journal of the Physical Society of Japa

    Barriers to implementation of a computerized decision support system for depression: an observational report on lessons learned in "real world" clinical settings

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    <p>Abstract</p> <p>Background</p> <p>Despite wide promotion, clinical practice guidelines have had limited effect in changing physician behavior. Effective implementation strategies to date have included: multifaceted interventions involving audit and feedback, local consensus processes, marketing; reminder systems, either manual or computerized; and interactive educational meetings. In addition, there is now growing evidence that contextual factors affecting implementation must be addressed such as organizational support (leadership procedures and resources) for the change and strategies to implement and maintain new systems.</p> <p>Methods</p> <p>To examine the feasibility and effectiveness of implementation of a computerized decision support system for depression (CDSS-D) in routine public mental health care in Texas, fifteen study clinicians (thirteen physicians and two advanced nurse practitioners) participated across five sites, accruing over 300 outpatient visits on 168 patients.</p> <p>Results</p> <p>Issues regarding computer literacy and hardware/software requirements were identified as initial barriers. Clinicians also reported concerns about negative impact on workflow and the potential need for duplication during the transition from paper to electronic systems of medical record keeping.</p> <p>Conclusion</p> <p>The following narrative report based on observations obtained during the initial testing and use of a CDSS-D in clinical settings further emphasizes the importance of taking into account organizational factors when planning implementation of evidence-based guidelines or decision support within a system.</p

    Magnetoelectric interaction and transport behaviours in magnetic nanocomposite thermoelectric materials

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    How to suppress the performance deterioration of thermoelectric materials in the intrinsic excitation region remains a key challenge. The magnetic transition of permanent magnet nanoparticles from ferromagnetism to paramagnetism provides an effective approach to finding the solution to this challenge. Here, we have designed and prepared magnetic nanocomposite thermoelectric materials consisting of BaFe12O19 nanoparticles and Ba0.3In0.3Co4Sb12 matrix. It was found that the electrical transport behaviours of the nanocomposites are controlled by the magnetic transition of BaFe12O19 nanoparticles from ferromagnetism to paramagnetism. BaFe12O19 nanoparticles trap electrons below the Curie temperature (TC) and release the trapped electrons above the TC, playing an ‘electron repository’ role in maintaining high figure of merit ZT. BaFe12O19 nanoparticles produce two types of magnetoelectric effect—electron spiral motion and magnon-drag thermopower—as well as enhancing phonon scattering. Our work demonstrates that the performance deterioration of thermoelectric materials in the intrinsic excitation region can be suppressed through the magnetic transition of permanent magnet nanoparticles
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