Effect of lead impurities on the amplitude-dependent absorption in normal and in superconductive indium

Journal Article · Mon Sep 01 04:00:00 EDT 1975 · Sov. J. Low Temp. Phys. (Engl. Transl.); (United States)

OSTI ID:7324987

Pal-Val, L N; Platkov, V Y

A study was made concerning the effect of small concentrations of lead impurities on the amplitude dependence of ultrasound absorption in normal and in superconductive indium. The frequency of longitudinal vibrations was 7.5 MHz. The single-crystal specimens for this study had all the same orientation. The ultrasonic waves were propagated in the (110) direction. Measurements were made at 1.4 and 77 degreeK. The lead content was varied from 1 x 10/sup -3/ to 3 x 10/sup -1/ at.%. In each case the transition to the n-state was accompanied by a shift of the absorption curve toward larger amplitudes. With the lead content increasing up to 3 x 10/sup -1/ at.%, the critical amplitude had increased more than 10/sup 3/ times. Implantation of impurity atoms had produced an appreciable change not dependent on the amplitude but nonmonotonically dependent on the impurity content: It first decreased and then slightly increased with increasing lead content. Unlike the amplitude-dependent absorption, this amplitude-independent absorption did not change during the s-transition at lead contents higher than c=5 x 10/sup -2/ at.%. These results indicate that the dynamic interaction between impurity atoms and dislocations contributes to the quasiviscous braking of the latter. As a result, the damping in doped single crystals does not change significantly during the s-transition. The change in conditions under which pinning centers are overcome by dislocations during the s-transition is attributed to a quasistatic mechanism. (AIP)

• Research Organization: Physicotechnical Institute of Low Temperatures, Academy of Sciences of the Ukrainian SSR
• OSTI ID: 7324987
• Journal Information: Sov. J. Low Temp. Phys. (Engl. Transl.); (United States), Journal Name: Sov. J. Low Temp. Phys. (Engl. Transl.); (United States) Vol. 1:9; ISSN SJLPD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360104* -- Metals & Alloys-- Physical Properties
656102 -- Solid State Physics-- Superconductivity-- Acoustic
Electronic
Magnetic
Optical
& Thermal Phenomena-- (-1987)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
DISLOCATION PINNING
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELEMENTS
IMPURITIES
INDIUM
LEAD
METALS
PHYSICAL PROPERTIES
SOUND WAVES
SUPERCONDUCTIVITY
ULTRASONIC WAVES