Silicon single crystal grains

Silicon nitride-based polycrystalline ceramic materials have the potential for structural applications at both room temperature and elevated temperatures, despite containing silicate/silicate-rich oxynitride grain boundary phases. These are generally much weaker compared to the silicon nitride single crystal grains of which the... 

Pentacene (Fig. 25.3) is a typically studied small molecular material since the charge transport properties were reported to be excellent (Farchioni and Grosso, 2001). As its important feature, pentacene can form the well-ordered thin film on oxidized silicon. The study shows that the smallest stable island consists of four molecules in monolayer films (Ruiz et al., 2003). The single-crystal grain can be achieved under appropriate growth conditions (Meyer zu Heringdorf et al., 2001). It also can be deposited on aluminum oxide and metal. Brinkmann et al. have shown that pentacene can be deposited onto polymer film (Brinkmann et al., 2003). 

Self-diffusion coefficients of nitrogen in polycrystalline alpha- and beta-silicon nitride were measured by using a gas-solid isotope exchange technique with as a tracer at 1200 to 14IOC. The diffusion coefficients for single-crystal grains could be expressed as ... 

The properties of silicon carbide (4—6) depend on purity, polytype, and method of formation. The measurements made on commercial, polycrystalline products should not be interpreted as being representative of single-crystal silicon carbide. The pressureless-sintered silicon carbides, being essentially single-phase, fine-grained, and polycrystalline, have properties distinct from both single crystals and direct-bonded silicon carbide refractories. Table 1 lists the properties of the fully compacted, high purity material. 

The microstructure of this compound deserves, in our opinion, a special discussion. A characteristic feature of the microstructure is the presence of strictly parallel shear lines in each grain. A similar effect is observed for grains of the main phase over the whole concentration range of silicon where it exists. In addition, striation is exhibited even after annealing an Mn4Si7 single crystal, obtained by a special method. 

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