aluminum silicide is a mixture of aluminum oxide, Al2O3, and silicon dioxide, SiO2, which may be anhydrous or hydrated. It can be obtained in the form of minerals or synthetically produced by smelting. The anhydrous alloy is known as kaolin, and the hydrated variety is used in manufacturing, such as ceramics. It is also commonly used in papermaking and as a coating for powdered foods.
It is also a key material in the production of aluminum cast alloys and has a number of industrial uses. It is often found in combination with other substances, such as alumina, to create refractory products. It is a brittle and hard mineral, with a Mohs scale hardness rating of 1-2. It is a refractory and has good resistance to corrosion and oxidation. It is a good thermal conductor and has a melting point of 2000degC.
Metallic aluminium and nickel silicide are common contact metallization materials for many semiconductor devices. Their use has been extended to other material systems such as gallium nitride and zinc oxide. Semiconducting b-phase iron silicide (FeSi2) is of particular interest for PV applications because it is earth abundant, nontoxic and has a suitable band gap19. Field-dependent two-terminal magnetoresistance at base temperature has been measured for aluminium and nickel silicide contacting the phosphorus d-layer. Figure 1a shows a small peak that results from weak localization in the d-layer and can be fitted with the Hikami model for disordered systems.