Compositional grading

Spectroscopic ellipsometry has also been applied in the characterization of compositionally graded a-SiC H alloys [353], where the flow ratio z —... 

Recently, composites of Ni-Al203 [58] and compositionally-graded Ni-P deposits containing SiC particles [59] were obtained using jet electroplating. The amount of SiC particles incorporated in the deposit could be controlled by the electrolyte jet velocity the incorporation increased from 0 to 30 vol.% as the jet velocity decreased from 16 to 0.5 m/s [59],... 

The combination of various SOFC component performance, microstructural, and property requirements has led to a variety of structures, such as the composite, graded, and multilayered electrodes and electrolytes described above. The need... 

Thermoplastics and Thermoplastic Composites Grades, processing and applications... 

Honeyman-Colvin, P., Lange, F.F., Infiltration of porous alumina bodies with solution precursors strengthening via compositional grading, grain size control, and transformation toughening, J. Am. Ceram. Soc., 79(7), 1810-1814, 1996. 

The imager of EP-A-0406696 is made up of a compositionally graded p-type base layer and a compositionally graded cap layer in which pn-junctions are formed. The structure has a small amount of leakage current and a large diode impedance. 

An alternative to the heterostructure is also shown. In this case, a compositionally graded structure is formed where the composition x of Hgi.xCdxTe varies with the distance from the passivation layer. Methods of manufacturing such structures are discussed. 

Once the base resistance problems are solved, the base transit time will be mi obstacle for high frequency operation due to the small diffusion constant, as estimated from the small mobility and the Einstein relation. A theoretical study on base transit time on GaN/InGaN HBTs [7] showed that a base transit time of less than 0.1 ps can be achieved with an appropriate base design by employing composition grading and/or doping grading. 

Properties Colorless crystals or white powder. Sp. gr. 3.244 at 23°. M. P. 575°. Gives green light on burning. Grade A (99.8 per cent purity) for use in priming compositions. Grade B (99.0 per cent purity) for use in pyrotechnic compositions. 

The extent of the slow state trapping depends on the quality of the dielectric layer (Street and Tsai 1986). Fig. 9.21 shows the slow charge trapping for nitrides which have a thin compositionally-graded layer at the interface consisting of material with a lower nitrogen concentration and therefore a smaller band gap than SigN. The concentration of slow... 

COMPOSITION-GRADED TRANSITIONAL BUFFERING FILM/ELECTROCOPPER... 

The combined gradual change in the methane-to-argon ratio and increase in discharge power resulted in the formation of a composition-graded film. During this cycle, the deposition rate of the methane plasma polymer decreased whereas that of copper or silver increased. 

Elecrocopper was plated onto the composition graded film layered by the double-graded process with oxygen and hydrogen treatment. 

STRUCTURE AND STABILITY OF COMPOSITION-GRADED TRANSITIONAL BUFFERING PHASE... 

Figure 21.7 Transmission electron micrograph (a) (x 88000) and electron diffraction pattern (b) of the composition graded transitional buffering fdm layered by double-graded process (1 copper electrode used 2 silver electrode used).

Figure 21.8 XPS spectra of the surface of composition graded transitional buffering film layered by double-graded process curve a, surface curve b, 1 min sputter curve c, 5 min sputter curve d, oxidized copper surface.

Table 21.7 Surface Chemical Analysis of Composition-Graded Film Layered by the Double-Graded Process [eopper eleetrode used] after Extended Time (48 h) Exposure to Atmosphere...

Figure 21.9 The proposed seetional model of a eomposition-graded transitional buffering film layered by double-graded proeess A, pure methane plasma polymer layer B, composition-graded layer of methane plasma polymer and metal C, sputtered metal layer with earbon contamination.

The stability of composition-graded films seems to be good because the adhesion value and chemical analysis data obtained by XPS do not show any significant changes after aging 2 months in a desiccator. 

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