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Plastic bend in a growing crystal
Author(s) -
Eidelman L. G.
Publication year - 1983
Publication title -
crystal research and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.377
H-Index - 64
eISSN - 1521-4079
pISSN - 0232-1300
DOI - 10.1002/crat.2170180317
Subject(s) - curvature , materials science , thermoelastic damping , condensed matter physics , lattice (music) , residual stress , crystal (programming language) , dislocation , diffraction , thermal , crystallography , geometry , mathematics , physics , optics , composite material , thermodynamics , chemistry , computer science , acoustics , programming language
Abstract In case of nonlinear axial temperature distribution the relaxation of thermoelastic stresses results in the plastic bend of the growing crystal, i. e. in the generation of a residual lattice curvature equal to ϱ b . Based on results from Billig and from Indenbom the author presents estimations of dislocation densities (ϱ) (i. e. residual lattice curvature) taking into account an elastic limit differing from zero. It is shown that sign and value of the residual lattice curvature may be effectively used as criteria pointing out how thermal conditions should be changed for abtaining more perfect crystals. This approach application allowed to grow larger KCl single crystals (300 mm in diameter more than 100 kg by weight) with better structure perfection (specific subboundaries surface 2—3 cm 2 /cm 3 , mean subgrain dimension 0.6—1 cm, mean mutual disorientation of subgrains of not more than 6′).