ISSN:0232-1300    

DOI:10.1002/crat.2170280528

出版商:WILEY‐VCH Verlag    

年代:1993

数据来源: WILEY

ISSN:0232-1300    

DOI:10.1002/crat.2170280529

出版商:WILEY‐VCH Verlag    

年代:1993

数据来源: WILEY

ISSN:0232-1300    

DOI:10.1002/crat.2170280530

出版商:WILEY‐VCH Verlag    

年代:1993

数据来源: WILEY

ISSN:0232-1300    

DOI:10.1002/crat.2170280531

出版商:WILEY‐VCH Verlag    

年代:1993

数据来源: WILEY

摘要:

AbstractA model is proposed for a description of the growth kinetics of long term finite melt liquid phase epitaxy of GaAs and GaAlAs layers. The applicability region of the model is discussed. The correct liquidus, the temperature dependence of the diffusion coefficients, the precise concentration profiles of the components of the melt, and the non‐equilibrium construction of atoms in the layer are taken into account. The influence of the crystallisation reaction at the surface of the layer is considered, and different temperature regimes of the process can be treated. Temperature dependences of the Al and As diffusion coefficients in the melt are determined, based on comparison between theoretical and experimental results for the thicknesses and the concentration profile of GaAs and GaAlAs growon (etched) layer

ISSN:0232-1300    

DOI:10.1002/crat.2170280502

出版商:WILEY‐VCH Verlag    

年代:1993

数据来源: WILEY

摘要:

AbstractThe growth of GaAlAs layers by a long term finite melt liquid phase epitaxy is studied expermentally. The influence of the technological parameters of the process upon the growth characteristics of the layer is investigated for a wide range of the technological parameters. In some cases computations of the layer characteristics are made, based on a model of the process. The data for the layer growth characteristics are in agreement with the theory predictions. The comparison of the computed and the experimental results allows the Al and As diffusion coefficients in the melt to be determined, as well as to find when the effect of the homogeneous crystallisation and the convection in the melt can be neglected.

ISSN:0232-1300    

DOI:10.1002/crat.2170280503

出版商:WILEY‐VCH Verlag    

年代:1993

数据来源: WILEY

ISSN:0232-1300    

DOI:10.1002/crat.2170280504

出版商:WILEY‐VCH Verlag    

年代:1993

数据来源: WILEY

摘要:

AbstractThe composition of scales formed in multiple evaporator units at three Australian sugar mills have been determined using X‐ray fluorescence (XRF), high performance liquid chromatography (HPLC), X‐ray diffraction (XRD), thermogravimetry/differential thermal analysis (TG/DTA) and other analytical methods. The composition of the scales formed in each mill have been found to be significantly different and to depend on whether they originated from early or later stages of the evaporation process. Calcium oxalate (present as the di and monohydrate) was identified as a major component of the scales from one mill but was found to be only a minor component of the scales from the other two. The latter were shown to contain two or more forms of calcium phosphate as dominant phases. Amorphous or crystalline silica was found to be present in most of the scales exami

ISSN:0232-1300    

DOI:10.1002/crat.2170280505

出版商:WILEY‐VCH Verlag    

年代:1993

数据来源: WILEY

ISSN:0232-1300    

DOI:10.1002/crat.2170280506

出版商:WILEY‐VCH Verlag    

年代:1993

数据来源: WILEY

摘要:

AbstractIn the present study the linear defects in several synthetic quartz have been surveyed by X‐ray topography using Lang method. The grown‐in dislocations produced by layers displacement around holes, precipitates or inclusions are discussed. Each growth zone is described with their own defects pattern and some correlations with the external morphology of the crystal are stated. There are also pointed out the asymmetry of the defects for every growth zone and the specific role in the growth mechanism of the s‐growth zone. In the final part of the work there are outlined the general and the specific conclu

ISSN:0232-1300    

DOI:10.1002/crat.2170280507

出版商:WILEY‐VCH Verlag    

年代:1993

数据来源: WILEY