Gallium with experimental values

In Table 8, the values for hardness calculated from formula (26) are compared with experimental values for various types of crystals. For gallium arsenide, we used experimental and theoretical results that indicate a net charge for the gallium atom of about 0.3-0 5. 

The values of rmet listed in Table 4.3.3 refer to 12-coordinate metal centers. Since not all metals actually adopt structures with equivalent 12-coordinate atoms such as the ccp structure, the rmet values are estimated from the experimental values. For the hep structure, there are two sets of six-coordinate atoms, which are not exactly equivalent to each other. In such circumstances, we usually adopt the average value of the two sets. Gallium possesses a complex structure in which each atom has one neighbor at 244 pm, two at 270 pm, two at 273 pm, and two at 279 pm, and its rmet can be estimated as 141 pm. 

During an investigation of the temperature dependence of the rate of hydrogen evolution at a liquid mercury-gallium alloy (containing 2.1 at. % Hg), very high values of the preexponential factor were observed in acidic as well as alkaline solutions. At least in acidic solutions, the experimental value (log k = 7.6) exceeded any reasonable theoretical estimates of the upper limits of the preexponential factor by several orders of magnitude[262]. Hence, it was naturally assumed that the experimental value was considerably distorted due to the dependence of the composition of the alloy surface on temperature. This assumption was verified with the help of the kinetic isotope effect. 

An approximate value of the interfacial tension between gallium and mercury was obtained, which agreed within experimental error with a much more accurate measurement made previously in this laboratory. 

Ga and P atoms increased to 0.43 electron/A . A comparison of the experimental atomic scattering factors of gallium and phosphorus with the theoretical Hartree-Fock factors [6] yielded the Debye—Waller factors B and the characteristic temperatures 0. Their values were used to determine also the mean-square dynamic displacements U yn. The following values were obtained for the gallium and phosphorus ions 0ca = 235 K, p — 360 K Bga 0.91 Bp = 0.89A2 (l Ga= 1-15 10 = A, = 1.12 10"2 A. ... 

For a one-dimensional gallium arsenide quantum well of width 21 nm, calculate the difference in energies between the n = 2 and n = 3 states for travel of conduction electrons across the width of the well. Compare your answer with the experimentally determined value of approximately 0.05 eV. 

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