Bridgman method

The variation with temperature of n and for an undoped GaAs crystal grown by the horizontal Bridgman method is shown in Fig. 3. The parameters that give the best fit to Eq. (12) are also shown. The power of this method is illustrated by the small probable errors in the fitted parameters, i.e., less than 15% for Nd and less than 1% for ED0. Very few techniques can lay claim to such accuracy. Note that for maximum reliability it is necessary to know the Hall r factor [Eq. (A 17)], since n = r/eR. A variational calculation, with NAS as the only undetermined parameter, was used to fit the fi versus T data, and also obtain r versus T (Meyer and Bartoli, 1981 Look et al., 1982a). 

Fig. 3. The temperature dependence of the electron concentration and electron mobility for a GaAs crystal grown by the horizontal Bridgman method. The solid curves are theoretical fits, as described in the text. [From Look et al. (1982a).]...

Fig. 3.46 Dislocation density versus As source temperature, Pas> for GaAs crystals grown by the Bridgman method. (Marks, J, and denote more than, less than, and nearly equal, respectively).

Figure 1. Arrangement for crystal growth by the Bridgman method. (Courtesy of R. K. Route.)...

Hitherto, the last two methods have not been used by electrochemists. They have either melted the tip of a wire so as to obtain a small sphere which in some cases is a single-crystal (platinum) or used a modified Bridgman method. 

Specimens were manufactured from single crystalline [i-NiAl with nearly stoichiometric composition (Al-content from 49 to 50at.%).The single crystals were prepared by the Bridgman method. Specimens for bend tests at RT were doped with about 0.1 at.% Fe and exhibited an enhanced RT ductility [23]. 

Monomer 238 crystallizes in a chiral structure of space group P2i. Its irradiation afforded the topological dimers and trimers as expected. When crystals were grown from the melt by the modified Bridgman method, the photodimer was obtained with ee up to 100% [184]. Another strategy to... 

The samples used in our investigation were prepared by different methods. Thus, samples 1-4 were the purest and were prepared by the floating molten zone method. Samples 5-6 were grown by the Bridgman method. Sample 7 was prepared by the Bridgman method from a melt containing 25 at.% of excess mercury. 

A maximum of the diffuse background was foimd in the spectrum of sample 7 (Fig. 2) on the left of the (200) selective reflection. This maximum was attributed to the presence of a second phase since it was not observed in the samples prepared by ihe floating molten zone method or by the Bridgman method (Fig. 3). 

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