Anisotropy of Microhardness and Fracture of Langasite Crystal and Its Structural Basis
The anisotropy of microhardness and fracture of the (0001) basal plane of langasite crystal has been studied using Berkovich indentation under a load of 100 g at different indenter positions. The formation of “crystallographic” microcracks (straight-line and emerging exactly from the impression angl...
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Published in | Crystallography reports Vol. 66; no. 6; pp. 1045 - 1050 |
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Main Authors | , , , |
Format | Journal Article |
Language | English |
Published |
Moscow
Pleiades Publishing
01.11.2021
Springer Nature B.V |
Subjects | |
Online Access | Get full text |
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Summary: | The anisotropy of microhardness and fracture of the (0001) basal plane of langasite crystal has been studied using Berkovich indentation under a load of 100 g at different indenter positions. The formation of “crystallographic” microcracks (straight-line and emerging exactly from the impression angles), which propagate in six directions, spaced by 60°, is observed. It is suggested that the observed specific features of microcrack formation are based structurally on the presence of a mixed cation site. As follows from the structural model of a multicell, fractures propagate along the direction of polyhedra with mixed cation occupancy, and the fracture line pushes apart unit cells of different chemical compositions. The Young’s modulus of langasite crystal has been calculated for different crystallographic planes. |
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ISSN: | 1063-7745 1562-689X |
DOI: | 10.1134/S1063774521060341 |