Basic oxide

Abstract: The viscosities of CaO-SiO2-20 wt%Al2O3-MgO slags (CaO/SiO2 = 1.0–1.2, wt%MgO = 5–13) were measured to estimate the effect of MgO on the viscous behaviour at elevated temperatures. The slag viscosity at 1773 K decreased with increasing MgO contents, which was typical of a basic oxide component at relatively low basicity (CaO/SiO2) of 1.0. The FT-IR spectroscopic analysis of the slag structure seems to verify this behaviour. However, an unexpected contradiction with the temperature dependence was observed above 10 wt%MgO and above CaO/SiO2 of 1.2. Although the apparent activation energy was expected to decrease with additions of the basic oxide component MgO, the apparent activation energy increased. This unexpected behaviour seems to be related to the change in the primary phase field correlating to the phase diagram corresponding to the slag composition. Therefore, in order to understand the viscosity at both high Al2O3 and MgO, not only should the typical depolymerization of the slag structure with high MgO content be considered but also the primary phases of which the molten slag originates.

Abstract: In order to develop a semiconductor type gas sensor applicable to the monitoring of N 2 O in air, a search for the semiconducting oxides sensitive to N 2 O was carried out. Among the 23 kinds of single oxides tested, SnO 2 turned out to give the highest sensitivity to N 2 O, although the sensitivity was not high enough. The N 2 O sensitivity was found to be promoted effectively when SnO 2 was loaded with a small amount of a basic oxide such as SrO, CaO, BaO, Bi 2 O 3 and Sm 2 O 3 . The promotion was particularly conspicuous with SrO loading. For example, 0.5 wt.% SrO-loaded SnO 2 , exhibited the N 2 O sensitivity about three times as high as that of pure SnO 2 , and could detect N 2 O in air fairly well in the concentration range of 10–300 ppm at 500°C.

Abstract: The semiconductor device of the present invention includes a semiconductor substrate on which are formed semiconductor elements, and a plurality of wiring layers formed on the semiconductor substrate via porous insulating films. The surface of the plurality of the wiring layers is preferably covered with a compact insulating film. The size of the pores in the porous insulating film is preferably 5 nm to 50 nm in diameter, and the volume of the pores in the porous insulating film is preferably 50% to 80% of the total volume of the porous insulating film. The porous insulating film is formed by subjecting a mixed insulating film of a basic oxide and an acidic oxide to a heat treatment to precipitate only either one of the basic oxide and the acidic oxide, and then dissolving out selectively the basic or acidic oxide precipitated.