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4.1. Morphology of crystals paratellurita and its communication with a crystallisation kinetics

Surfaces of the crystals which have been grown up by a method Chohralsky, reflect, besides devices proper in them ogranenija, fluctuations of temperature and growth rates. Therefore in the present operation of a surface of crystals paratellurita have been studied by means of various equipment and at various magnifications.

C the help of a raster-type electronic microscope «JEOE» had been gained images of lateral surfaces of monocrystals paratellurita (drawings 4). Elektronno-microscopic images show, that on them periodic variations of diameter of the crystals, corresponding to three spatial and temporary gauges-5 a micron, 50 microns, 500 microns are observed; 30с, 300с, 3000с.

Fig. 4.1 - Images of a lateral surface of a monocrystal paratellurita.

Magnification? 40

Fig. 4.2 - Images of a lateral surface of a monocrystal paratellurita. Magnification? 100

Fig. 4.3 - Images of a lateral surface of a monocrystal paratellurita. Magnification? 2000

The further examinations of a surface were spent by means of the interference profilometra NanoMap 1OOOWLI. There were, that corners which make sites of a surface of the crystal, corresponding periodic razrashchivanijam and podplavlenijam, are not identical. It is well visible on profilogramme a site of a lateral surface of a monocrystal paratellurita, gained by an expedient Chohralsky at the true velocity of vertical growth equal 0,4 mm/hour (drawing 4.4). C the direction account vytjagivanija (drawing 4.4 - on the right), fusion occurs more slowly, than growth. Really, corners between inclines of unevennesses corresponding to magnification of diameter of a crystal and an axis vytjagivanija, it is more than corresponding corners for the inclines coinciding with the moments of reduction of diameter. The given fact confirms asymmetry of processes of growth and fusion of crystals.

Drawing 4.4 - profilogramma a site of a lateral surface of a monocrystal paratellurita with microsalients

The morphology of fronts of crystallisation has been explored also, including, corresponding to crystal growth paratellurita with major velocity (to mm a second) and at major supercoolings till 20-30 K.Na drawing 4.5 is shown a surface of a separation of a crystal paratellurita from a melt with the macrosalients forming system of enclosed octagons. Them

The legs correspond to facets of the equilibrium shape {110}, {101} and {FROM}, explored in operation [123]. Long salients in a view dendritov correspond to a direction [001] spotted in [123] as direction with peak temperaturoprovodnostju paratelurita. They were formed at the peak supercoolings and growth rates.

Drawing 4.5 - the Monocrystal paratellurita, extended in the inferior part at major supercoolings of a melt, with outgrowths in a direction [001]

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A source: Aydinyan Narek Vaagovich. the KINETICS of GROWTH of LARGE-SIZED MONOCRYSTALS paratellurita And Germany In the METHOD of the CHOHRALSKY. The dissertation on competition of a scientific degree of the candidate of physical and mathematical sciences. Tver - 2017. 2017

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  13. Ajdinjan Has named Vaagovich. the KINETICS of GROWTH of LARGE-SIZED MONOCRYSTALS paratellurita And Germany In the METHOD of the CHOHRALSKY. The dissertation on competition of a scientific degree of the candidate of physical and mathematical sciences. Tver - 2017, 2017