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541.
C. Pietsch E. Buhrig H. Boudriot K. Deus W. Siegel 《Crystal Research and Technology》1977,12(12):1285-1292
In the solution growth of ternary semiconductors tin can be used as solvent. In this case the phase purity resp. the generation of a solid solution of the reaction products obtained is of interest. This problem was investigated using the growth of ZnSiP2 from tin solutions. For characterizing the phases obtained by the growth X-ray diffraction. Mössbauer spectroscopy, electronoprobe analysis, luminescence spectroscopy, DTA-measurements and electrical measurements were used. The results of these measurements allow the following statements within the limits of measuring.
- 1 The growth of the pure ZnSiP2 from tin melts is possible.
- 2 The phases ZnSnP2 and ZnSiP2 are generated side by side by a nonstoichiometric amount weighed of silicon.
- 3 The solubility of ZnSnP2 in ZnSiP2 or reverse could not be pointed out.
- 4 The precipitation of ZnSnP2 on ZnSiP2 takes place epitaxially.
542.
The electron-probe microonalysis provides a variety of informations on the condition of mettalic samples within the micro range, which in connection with an appropriate measuring technique enables numerous statements to be made on important metallographic problems. As examples from the operating practice of a high-quality steel plant the identification of structural constituents, determination of microsegregation, investigation of grain boundaries and material defects in steels are explained. 相似文献
543.
W. Siegel H. Boudriot H. Koi K. Deus O. Oettel H. A. Schneider 《Crystal Research and Technology》1989,24(10):999-1002
GaAs: Si with different doping level was grown by the gradient freeze method. The crystals were characterized by structural, electrical and optical methods concerning especially the dependence of the epd and the compensation degree on the carrier concentration. 相似文献
544.
The properties of ZnSiP2 crystals prepared by adding of Ga and In to the melt differ essentially from that of undoped samples. Especially the activation energies determined from the temperature dependence of the Hall coefficient prove that in both cases a real doping with shallow impurities has taken place. Ga and In act as donors suggesting the conclusion that Ga and In atoms substitute Zn atoms. The existence of strong electrical inhomogenities in a part of the samples is discussed. 相似文献
545.
546.
H. Becherer E. Buhrig K. Hein M. John P. Kirsten H. A. Schneider W. Siegel K. Winkler 《Crystal Research and Technology》1978,13(9):1053-1057
Undoped ZnSiP2 crystals grown by different methods (vapour phase transport, solution growth) show in part considerable differences in their physical properties. The connections between growth, quality of the basic materials and the physical properties of ZnSiP2 will be shown. Measurements of Hall effect, resistivity, luminescence and backscattering of protons yielded informations about the perfection and homogenity of the crystals and about the impurities and recombination centres characteristically for the various growth methods. The influence of doping by different elements on the properties of solution grown ZnSiP2 crystals was investigated. 相似文献
547.
Hydrogels based on lightly crosslinked poly(methacrylamidophenylboronic acid-co-acylamide) swell monototically at pH 7.4 with exposure to increasing concentrations of glucose. At pH 10 these hydrogels first shrink and then reswell with increasing glucose concentration. A mechanism for these disctinct behaviors is proposed and preliminary results validating this mechanism are presented. A simple microfabricated glucose-sensitive valve based on this hydrogel is described. 相似文献