Ultrasonic attenuation of longitudinal and shear waves in superconducting lead

Journal Article · Mon Jun 01 04:00:00 EDT 1987 · J. Low Temp. Phys.; (United States)

DOI:https://doi.org/10.1007/BF00710354· OSTI ID:6094697

Philip, J; Basu, B K; Samudravijaya, K

Longitudinal and shear wave ultrasonic attenuations have been measured in high-purity Pb on two single crystals obtained from the same ingot. The measurements were done at low temperatures, at different frequencies, and in transverse magnetic fields, up to a field of 7.3 kG. The propagation directions in the two crystals were along (100) and (110). For some propagation and polarization directions the ..cap alpha../sub s//..cap alpha../sub n/ ratio is found to be frequency-independent, while for others, large divergences in the ..cap alpha../sub s//..cap alpha../sub n/ ratios at different frequencies are observed. A sharp decrease of ..cap alpha../sub s/..cap alpha../sub n/ near T/sub c/ is observed for a particular longitudinal wave propagation, but not in any shear wave propagation. In some cases ..cap alpha../sub s//..cap alpha../sub n/ is found to be abnormally high and this feature is associated with a peak in attention ..cap alpha../sub n/ and a relatively high ..cap alpha../sub n/ at 7.2 K. None of the ..cap alpha../sub s//..cap alpha../sub n/ curves fits closely to any BCS energy gap. For longitudinal waves the high magnetic field (H) dependence of the normal state attenuation was found to agree qualitatively with the free electron theory for propagation along (100), but not for propagation along (110). For shear waves the high-field attenuations do not extrapolate to zero as H tends to infinity. For all propagation and polarization directions the high-field attenuations show 1/H/sup 2/ field dependence.

• Research Organization: Cochin Univ., India
• OSTI ID: 6094697
• Journal Information: J. Low Temp. Phys.; (United States), Journal Name: J. Low Temp. Phys.; (United States) Vol. 67:5-6; ISSN JLTPA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360102 -- Metals & Alloys-- Structure & Phase Studies
360104* -- Metals & Alloys-- Physical Properties
ACOUSTIC TESTING
ATTENUATION
BCS THEORY
CRYSTAL DEFECTS
CRYSTAL STRUCTURE
CRYSTALS
DISLOCATIONS
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELECTRONS
ELEMENTARY PARTICLES
ELEMENTS
ENERGY GAP
FERMIONS
FREQUENCY DEPENDENCE
FREQUENCY RANGE
LATTICE PARAMETERS
LEAD
LEPTONS
LINE DEFECTS
MAGNETIC FIELDS
MATERIALS TESTING
MEAN FREE PATH
METALS
MHZ RANGE
MHZ RANGE 01-100
MONOCRYSTALS
NONDESTRUCTIVE TESTING
PHYSICAL PROPERTIES
PIPPARD THEORY
SHEAR
SOUND WAVES
SUPERCONDUCTIVITY
SUPERCONDUCTORS
TEMPERATURE DEPENDENCE
TESTING
ULTRALOW TEMPERATURE
ULTRASONIC TESTING
ULTRASONIC WAVES
VELOCITY
WAVE PROPAGATION
WAVELENGTHS