Superlattices resistivity

For local deviations from random atomic distribution electrical resistivity is affected just by the diffuse scattering of conduction electrons LRO in addition will contribute to resistivity by superlattice Bragg scattering, thus changing the effective number of conduction electrons. When measuring resistivity at a low and constant temperature no phonon scattering need be considered ar a rather simple formula results ... 

Thus, it is concluded that the FCC structure induces an increase in the tunneling rate i.e., the resistance decreases between particles. The tunneling between adjacent particles is a major contribution to the conduction. This inhibits the Coulomb blockade in the tunneling I V) measurements, and thus the 3D superlattices yield an increased tunneling current. 

Figure 6.75 Variation in resistivity of two ironchromium superlattices of various layer thicknesses due to magnetoresistive effect. Reprinted, by permission, from P. Ball, Made to Measure, p. 77. Copyright 1997 by Princeton University Press.

The room-temperature resistivity of the superlattice material in the plane of the layers is shown in Fig. 10 as a function of the a-Si H layer thickness Lg for a fixed a-SiN H layer thickness of 35 A and a total film thickness of... 

Fig. 12. Resistivity in the plane of layers, p, as a function of number of periods M in a-Si H/a-SiN H superlattice for diflFerent a-Si H layer spacing i The full curves were computed from Eq. (7) for the energy-band model given in Fig. 13. Experimental L, (A) = 1200 (V), 400 (O), 160 ( ), 80 (O), 40 (A). [From Tiedje and Abeles (1984).]...

Boron-carbon-nitride ceramic is deposited on iron-based sliding parts by chemical vapor deposition (CVD) it is used as rotary compressor shafts, in order to improve the wear resistance [1 to 5]. Such B-C-N coatings have also been applied to dynamic pressure air bearings [6]. In gas-cooled nuclear reactors, °B-enriched B-C-N can be deposited by CVD in the fluid channels of the fuel elements for permanent deactivation in case of an emergency [7]. Radiofrequency or microwave-enhanced CVD is employed in order to deposit a diamond carbon and (3-BN superlattice structure [8]. 

Several important areas have been omitted. One area is defects in solids. Calculations in impurities, vacancies, interstitials, line defects, and plane defects have been performed using similar methods. Another area is interfaces. Applications are being made to the metal-semiconductor interfaces (Schottky barriers), semiconductor-semiconductor interfaces (heterojunctions), and superlattices. The study of molecules and clusters is a third area. Also, since the method can be used to calculate electron-phonon couplings, phenomena such as resistivity, superconductivity, ultrasonic attentuation, and so forth, can now be studied using these ab initio methods. Results from research in all these areas have been impressive and very encouraging. 

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