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Electromagnetic Emission from Impact‐Loaded Polycrystalline A 2 B 6 Materials
Author(s) -
Chmel Alexandre,
Dunaev Anatolij,
Shcherbakov Igor
Publication year - 2018
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.201800112
Subject(s) - crystallite , materials science , acoustic emission , dislocation , mechanoluminescence , ionic bonding , excitation , ceramic , composite material , ion , metallurgy , chemistry , optoelectronics , physics , phosphor , organic chemistry , quantum mechanics
The electromagnetic emission (EME) from deformed ionic single crystals occurs due to the motion of charged dislocations. Observations of the EME from polycrystalline ductile materials have never been reported. Meanwhile, the boundaries between crystallites play the role of the natural barriers for sliding dislocations; therefore, one can expect that the character and degree of heterogeneity might affect substantially the manifestation of the EME excitation. This study presents results of the observation of the EME excited by the impact loading of ductile ionic‐covalent A 2 B 6 ceramics. Continuous emission in the range of 10–100 kHz manifests itself in ZnS, ZnSe, and ZnTe compounds. This low‐frequency EME is supplemented with sporadic peaks emitted in the megahertz range. The continuous EME is ascribed by the motion of dislocations in crystallites, while the discrete high‐frequency emission is suggested to be due to discharges between edges of cracks nucleated at the final stage of the damage formation. The intercomparison of the EME time sweeps with the records of the mechanoluminescence and acoustic emission detected in parallel with the EME shows that the primary plastic deformation in the polycrystalline A 2 B 6 compounds is followed by the accumulation of microcracks.