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22AIST TODAY 2013-1Hidekazu SAITOUSpintronics Research CenterAIST TODAY Vol.12 No.11 p.16 (2012) Storing spin information in germanium at room temperatureDevelopment toward a novel transistor with ultra-low power consumptionSpintronics, a new type of technology, has recently attracted much attention because of its potential to reduce the power consumption of electronic devices, which are indispensable in our present life. It has been expected that a “spin transistor” with ultra-low power consumption can be realized if the spin information of a magnetic material can be transferred to a semiconductor.We have demonstrated the transfer of spin information from iron into p-type germanium at room temperature. Germanium is a promising candidate as the semiconductor material for next-generation MOS transistors. This achievement is an important breakthrough in the development of a spin transistor with prospective application in the so-called green information technology.Novel preparation technique enhancing oxidation activity of Pt catalystsFormation of efficient contacts between Pt and promoter that enables CO oxidation below room temperatureThe use of additives to promote catalytic reactions over platinum group metals (PGMs) is employed in various applications. To optimize interactions between PGMs and promoters, it is necessary for uniform contacts to exist between them. We have developed a preparation technique of Pt catalyst that enables CO oxidation at low temperatures. Concretely, Pt/Fe-containing alumina catalysts were prepared and treated with water under moderate conditions. From structural analyses of the catalysts, it was concluded that Pt nanoparticles and iron oxides formed efficient contacts in the catalysts probably because of the enhanced mobility of Pt species. Surprisingly, these catalysts could catalyze CO oxidation at low temperatures—even below 0 ℃. The concept of interface fabrication demonstrated in this example provides an opportunity to significantly reduce the use of PGMs in catalysts.Schematic image of the device structure for observation of spin signalHAADF-STEM image and optical photograph of the developed catalystPt particles having diameters of ≈ 1.5 nm are highly dispersed on the support.Spin signal of germanium at room temperature (red circle)Temperature dependence of CO conversions over the catalysts in (1 % CO + 0.5 % O2)/N2Information Technology and Electronics Nanotechnology, Materials and ManufacturingRoom temperatureMagnetic field (T)Hanle signal (mV)0.0-0.2-0.40.20.40.000.050.100.15CO conversion / %100806040200-50050100150200Temperature / ℃1 wt%Pt/Fe-Al2O3 developed catalyst 1.5 wt%Au/TiO25 wt%Pt/Al2O3commercialcatalystAtsuko TOMITAYutaka TAIMaterials Research Institute for Sustainable DevelopmentAIST TODAY Vol.12 No.10 p.17 (2012)p-type germanium VICurrent sourceMagnetic fieldVoltage meterIronMagnesium oxide

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