| Issue |
J. Phys. Colloques
Volume 46, Number C10, Décembre 1985
Eighth International Conference on Internal Friction and Ultrasonic Attenuation in Solids
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| Page(s) | C10-521 - C10-524 | |
| DOI | https://doi.org/10.1051/jphyscol:198510115 | |
Eighth International Conference on Internal Friction and Ultrasonic Attenuation in Solids
J. Phys. Colloques 46 (1985) C10-521-C10-524
DOI: 10.1051/jphyscol:198510115
Physics and Engineering Laboratory, DSIR, Lower Hutt, New Zealand
J. Phys. Colloques 46 (1985) C10-521-C10-524
DOI: 10.1051/jphyscol:198510115
DISLOCATION CHARGE IN ALKALI HALIDES DETERMINED FROM INTERNAL FRICTION AND PIEZOELECTRIC DEFECT MEASUREMENTS
W.H. ROBINSON, J.L. TALLON and R.G. BUCKLEYPhysics and Engineering Laboratory, DSIR, Lower Hutt, New Zealand
Abstract
By using the ultrasonic composite oscillator operating at 40 kHz and strain amplitudes of 10-10 to 2x10-4, it is possible to determine the internal friction, the modulus defect and the direct and converse piezoelectric defect due to charged dislocations in bent alkali halide single crystals. A model independent equation linking these terms enables the determination of the electrical charge on the dislocations together with the dislocation displacement. The temperature at which the mean dislocation charge vanishes is the isoelectric temperature, Te and from its temperature dependence the vacancy formation parameters have been calculated. We also find that Te is weakly dependent on the strain amplitude.