In this study, the important roles of chemical stoichiometry and hot electrons in realizing the stable bipolar resistive transition of sputter-deposited silicon oxide films were demonstrated. It was also clearly demonstrated that the injection of “hot” electrons from the silicon substrate induces stable resistive transitions for a low concentration of suboxide and metallic Si atoms, and that the injection of “cold” electrons from the silicon substrate does not induce stable resistive transitions in spite of the inclusion of metallic Si atoms in the oxide films. However, it was shown that the specific metal top electrode that does not react with oxygen ions is useful as the electron injector and temporal oxygen-ion pocket for the stable resistive transition of sputter-deposited silicon oxide films.

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In recent years, magnesium alloys are attracting attention from aircraft and automotive industries because of their low density, high speci c strength and high damping capacity. However, magnesium alloys suffer from low ductility at room temperature. The improvement of ductility in AZ91D alloy through a new thermo-mechanical treatment (TMT) process was reported. This TMT process is based on simple uniaxial hot pressing in atmosphere. Uniaxial hot pressing was carried out at 673 K up to 67% compressive strain. After the hot pressing, the specimen was held isothermally at 673 K for various times. Hot pressed specimens were aged at 473 K. The specimen isothermally held for 3.6 ks showed tensile strength of 358 MPa and elongation to failure of 9.6%. Microstructural observation revealed that both high strength and ductility in AZ91D alloy were caused by the homogeneous distribution of ne intermetallic precipitates inside grains.

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