Charge density wave transition and superconductivity in 2H-NbSe/sub 2/. Direct measurement of the penetration depth in a layered superconductor

Journal Article · Tue Jan 01 00:00:00 EST 1985 · J. Low Temp. Phys.; (United States)

DOI:https://doi.org/10.1007/BF00682569· OSTI ID:5838385

Takita, K; Masuda, K

The Schawlow-Devlin self-inductance method of direct measurement of the penetration depth has been adopted for layered superconductors, for which this method is especially suitable because the calibration procedure is very simple for them. The ratio of coherence length to mean free path xi/sub 0//l within the layer is deduced from the penetration depth measured by the new method and the resistivity, and is found to be 0.14 for a pure crystal of 2H-NbSe/sub 2/ with RRR of about 50. The effect of the CDW transition on the superconductivity in 2H-NbSe/sub 2/ is investigated through the measurement of the penetration depth. In addition to pure crystals, some modified crystals are investigated where the CDW transition is suppressed. The London penetration depth lambda/sub L/(0) as well as the superconducting transition temperature T/sub c/ show a slight but apparent increase with decreasing CDW transition temperature T/sub D/ of the samples. Both behaviors may be explained by a decrease in the reduction of N(E/sub f/) due to the suppression of the CDW transitions, where N(E/sub F/) is the density of states at the Fermi energy. The result also suggests a systematic increase of the ratio of effective mass to electron density m/sub parallel//n of the electron system with the suppression of the CDW transition.

• Research Organization: Institute of Materials Science, University of Tsukuba, Ibaraki, Japan
• OSTI ID: 5838385
• Journal Information: J. Low Temp. Phys.; (United States), Vol. 58:1
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
NIOBIUM SELENIDES
SUPERCONDUCTIVITY
COHERENCE LENGTH
CRITICAL FIELD
ENERGY-LEVEL DENSITY
FERMI LEVEL
LAYERS
PENETRATION DEPTH
PLASMA WAVES
TEMPERATURE DEPENDENCE
ULTRALOW TEMPERATURE
CHALCOGENIDES
DIMENSIONS
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ENERGY LEVELS
LENGTH
MAGNETIC FIELDS
NIOBIUM COMPOUNDS
PHYSICAL PROPERTIES
REFRACTORY METAL COMPOUNDS
SELENIDES
SELENIUM COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
360603* - Materials- Properties
656102 - Solid State Physics- Superconductivity- Acoustic
Electronic
Magnetic
Optical
& Thermal Phenomena- (-1987)