Apparatus for the deposition of low frequency cadmium sulphide transducers

Llewellyn, J D; Montagu-Pollock, H M; Dobbs, E. R.

doi:10.1088/0022-3735/2/6/420

Cited by 10 publications

(1 citation statement)

References 3 publications

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“…This is expected as these hexagonal close packed metals slip mainly in the basal plane (Friedel 1964) and hence the only ultrasonic waves which interact with the dislocation network are those with a component of shear stress in the basal plane. This conclusion has also been verified for zinc by W aterman (1958) and for cadmium by Abowitz (1963) and by Mason & Rosenberg (1969).…”

Section: 2mentioning

confidence: 54%

Ultrasonic studies of the electronic structure of hexagonal metal crystals. I. Normal state in magnesium, zinc and cadmium

Lea

Llewellyn

Peck

et al. 1973

Proc. R. Soc. Lond. A

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Measurements have been made of the total electronic attenuation α , in the low temperature limit, of longitudinal ultrasound propagating along the <0001>, <10͞10>, and <11͞20> directions in pure magnesium, zinc and cadmium crystals. In magnesium this attenuation was obtained from data taken from 1.2 to 80 K and in zinc and cadmium from the application of the critical magnetic field in the superconducting state at 0.1 K. In the high-frequency limit α is proportional to the frequency of the sound v and values of N = lim ( α/v ) have been found by extrapolation from measurements between 30 and 450 MHz. For magnesium N = 0.20±0.01 dB cm -1 MHz -1 for all three propagation directions; in zinc N = 1.29, 0.143 and 0.067 dB cm -1 MHz -1 (±5%) for sound propagation along <0001>, <10͞10> and <11͞20> directions respectively. For cadmium the corresponding values are 0.99, 0.165 and 0.048 dB cm -1 MHz -1 (±5%). The anisotropy in N is partly due to elastic anisotropy and partly to the Fermi surface geometry. In zinc and cadmium, our measurements are in agreement with the Fermi surface due to Stark & Falicov (1967), in which the ‘butterflies’ and ‘cigars’ are absent. We have deduced average values of the deformation parameter K x for magnesium, zinc and cadmium, using the theory of Pippard. We show that the deformation parameter for strains along the c -axis in zinc and cadmium is much greater than for strains in the basal plane, whereas magnesium is isotropic. Electron mean free paths l u deduced from the ultrasonic data are compared with those obtained from resistivity measurements on our samples. Anisotropies in l u are attributed partly to Fermi surface geometry and partly to small angle scattering.

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Section: 2mentioning

confidence: 54%