摘要:

AbstractSpontaneous isothermal transformation of negative crystals (vapcur inclusions) at temperatures close to the melting point is experimentally studied. Linear dependence of the transformation rate on supersaturation is established. This result shows that the evaporating crystal surfaces of the inclusions are moleculary‐rough. Surface self‐diffusion has no appreciable contribution to the transformation process of the molecularly‐rough surfaces of dip

ISSN:0232-1300    

DOI:10.1002/crat.2170171002

出版商:WILEY‐VCH Verlag    

年代:1982

数据来源: WILEY

摘要:

AbstractThe stability of the process of crystallization in the Verneuil techniques is analyzed, taking into account the geometrical shape of the molten layer surface and specific features of the heat and mass transfer typical for this method of crystal growth. The process is stable for crystal radii below the capillarity constant.

ISSN:0232-1300    

DOI:10.1002/crat.2170171003

出版商:WILEY‐VCH Verlag    

年代:1982

数据来源: WILEY

摘要:

AbstractThe authors analyze the process of corundum tube growth by modified Verneuil's method from the viewpoint of its stability. The article shows that the process is stable in the case of thin‐walled tubes and becomes unstable when the tube wall thickness exceeds a certain critical value which is known to be below the capillary constant. The critical thickness of the tube wall grows with a decrease of the heat flux density differential from the burner along the furnace muffle and with an increase of the tube's outer radius.As a result of a process of crystal growth under preset conditions constant cross‐section single crystaal corundum tubes have been obtai

ISSN:0232-1300    

DOI:10.1002/crat.2170171004

出版商:WILEY‐VCH Verlag    

年代:1982

数据来源: WILEY

摘要:

AbstractSingle and transparent crystals of potassium sulphate up to 30 × 3 × 3 mm in size have been grown by silica gel technique, using various methods (two‐layers three‐layers and hybrid gel technique) which are described. The effects of the three differents alcohols (used as top solutions) upon the quality and nucleation of crystals are also reported. The “growth and equilibrium” morphologies and microstructures of the habit faces are

ISSN:0232-1300    

DOI:10.1002/crat.2170171005

出版商:WILEY‐VCH Verlag    

年代:1982

数据来源: WILEY

ISSN:0232-1300    

DOI:10.1002/crat.2170171006

出版商:WILEY‐VCH Verlag    

年代:1982

数据来源: WILEY

摘要:

AbstractStarting from the gas‐phase‐transport‐controlled and reaction‐controlled incorporation mechanisms and the equilibrium incorporation of the dopants a critical study of the adsorption model is carried through, as a result of which a model of adsorption is proposed. This modified model reflects the incorporation concentration of the dopants as a function of the layer growth rate and contains the equilibrium incorporation of dopants as a border‐line case for a layer growth rat

ISSN:0232-1300    

DOI:10.1002/crat.2170171007

出版商:WILEY‐VCH Verlag    

年代:1982

数据来源: WILEY

ISSN:0232-1300    

DOI:10.1002/crat.2170171008

出版商:WILEY‐VCH Verlag    

年代:1982

数据来源: WILEY

摘要:

AbstractEquilibria between quaternary liquid phases Ga–In–As–Ge(–Sn) and the ternary solid phase Ga–In–As have been calculated by application of the KRUPKOWSKIformalism on the excess free enthalpy. Experimental liquidus data were obtained from solubility experiments in a LPE equipment. Results of calculation and experimental liquidus data a

ISSN:0232-1300    

DOI:10.1002/crat.2170171009

出版商:WILEY‐VCH Verlag    

年代:1982

数据来源: WILEY

摘要:

AbstractThe lattice parameters of Bi1–xSbxsingle crystals were measured for 0 ≦x≦ 1 by a special X‐ray diffractometer technique using reflections chosen so that minimum errors were achieved. Corrections for thermal expansion and refraction were applied. The antimony concentration was determined by means of electron microprobe analysis. The dependences of the lattice parameters onx(in nm) can be described with good approximation bya= 0.45469 – 0.02398xandc= 1.186294 – 0.058632 [1 + 1.26 (x−1– 1)]−1, resp. The behaviour of the parameterais in agreement with the earlier study by CUCKAand BARRETT, whereas their linear expression forc(x) (0 ≦x≦ 0

ISSN:0232-1300    

DOI:10.1002/crat.2170171010

出版商:WILEY‐VCH Verlag    

年代:1982

数据来源: WILEY

ISSN:0232-1300    

DOI:10.1002/crat.2170171011

出版商:WILEY‐VCH Verlag    

年代:1982

数据来源: WILEY