ISSN:0023-4753    

DOI:10.1002/crat.19790140716

出版商:WILEY‐VCH Verlag    

年代:1979

数据来源: WILEY

ISSN:0023-4753    

DOI:10.1002/crat.19790140717

出版商:WILEY‐VCH Verlag    

年代:1979

数据来源: WILEY

ISSN:0023-4753    

DOI:10.1002/crat.19790140718

出版商:WILEY‐VCH Verlag    

年代:1979

数据来源: WILEY

ISSN:0023-4753    

DOI:10.1002/crat.19790140719

出版商:WILEY‐VCH Verlag    

年代:1979

数据来源: WILEY

摘要:

AbstractIn Ni single crystals grown by the floating‐zone method, it was found that their growth directions tended to concentrate towards the 〈111〉 or the 〈100〉 direction. An interpretation was put forward for the preferred direction of these crystals in terms of thermal stability of the crystallographic planes in the solid‐liqui

ISSN:0023-4753    

DOI:10.1002/crat.19790140702

出版商:WILEY‐VCH Verlag    

年代:1979

数据来源: WILEY

摘要:

AbstractIn einer vorangegangenen Arbeit wurde gezeigt, daß Pseudosymmetrien die Kristalltracht organischer Kristalle beeinflussen. Das morphologische Gitter von Strukturen mit zwei kristallographisch unabhängigen Molekülen in der Elementarzelle entspricht dem Gitter der Zentren zwischen beiden Molekülen. Dies kann mit Hilfe „morphologischer Auslöschungsregeln”︁ nachgewie

ISSN:0023-4753    

DOI:10.1002/crat.19790140703

出版商:WILEY‐VCH Verlag    

年代:1979

数据来源: WILEY

摘要:

AbstractInvestigations made on the etching behaviour of magnesium orthosilicate crystals in hydrochloric acid and melts of potassium and sodium hydroxides are described. It is shown that the morphology and orientation of the etch pits depend upon the concentration, composition and temperature of the etchant used. At low concentrations of HCl acid solution, the boat shaped pits produced are oriented along [100] direction while in concentrated acid, the hexagonal pits produced are oriented along [001]direction. At intermediate concentrations of about 5 N HCl acid the pits are square. KOH melt at 400 °C is found to produce rectangular pits with their longer sides parallel to [100] direction. The effect of a mixture of KOH and NaOH in different proportions in the melt is investigated. It is observed that square pits are obtained in melt of the mixture of KOH and NaOH in the proportion of 6:4 respectively. The mechanism responsible for the change in orientation of etch pits have been explained. The implications are discussed

ISSN:0023-4753    

DOI:10.1002/crat.19790140704

出版商:WILEY‐VCH Verlag    

年代:1979

数据来源: WILEY

摘要:

AbstractThe real structure and the mechanical properties of pure and doped corundum single crystals have been investigated. The single crystals were obtained by the Verneuil‐method. The results allow to propose two different models concerning the influence of the chromium and titanium oxide on the properties of corundum single crystals.Optimum concentration of the chromium oxide impurities was approximately determined, from which corundum single crystals with higher hardness can be obtained. It was stated that titanium oxide impurities with some concentrations made the crystals more fragile without plastically changes in the region of the individual mosaic block

ISSN:0023-4753    

DOI:10.1002/crat.19790140705

出版商:WILEY‐VCH Verlag    

年代:1979

数据来源: WILEY

摘要:

AbstractThis paper describes investigations on process induced crystal defects in n‐type silicon material of both Czochralski‐ and zone‐floating‐techniques (dislocation‐free). The heating and cooling processes, the oxide thickness, mechanical stresses near the diffusion windows, the mask pattern geometry concerning diffusion and the surface concentration of the doping material have been specially investigated. The influence of those technological parameters on the generation of crystal defects in the production of electronic devices is investigated and

ISSN:0023-4753    

DOI:10.1002/crat.19790140706

出版商:WILEY‐VCH Verlag    

年代:1979

数据来源: WILEY

摘要:

AbstractThe static and dynamic pretransitional behaviour was investigated by the electric Kerr effect in three nematic substances above the clearing point. The measured Kerr constants exceed that of nitrobenzene by more than a factor of 50…︁ 80 which are due mainly to pretransition phenomena and the strong dipole moments of the compounds. A formula is given for the calculation of the Kerr constant. The latent heat at the nematic‐isotropic phase transition calculated from the temperature dependence of the Kerr constant by means of the Landau theory is in good agreement with the experimental values. Size and relaxation behaviour of pseudonematic domains are determined by Kerr effect measure

ISSN:0023-4753    

DOI:10.1002/crat.19790140707

出版商:WILEY‐VCH Verlag    

年代:1979

数据来源: WILEY