Specific heat and resistivity near the charge-density-wave phase transitions in 2H-TaSe/sub 2/ and 2H-TaS/sub 2/

Journal Article · Tue Nov 15 00:00:00 EST 1977 · Phys. Rev., B; (United States)

DOI:https://doi.org/10.1103/PhysRevB.16.4583· OSTI ID:5242924

Craven, R A; Meyer, S F

Detailed measurements of the specific heat and resistivity have been made on samples of 2H-TaSe/sub 2/ and 2H-TaS/sub 2/ near their charge-density-wave phase transitions. Because the crystal quality of 2H-TaSe/sub 2/ is much better than that of 2H-TaS/sub 2/, we emphasize the results on 2H-TaSe/sub 2/ and make quantitative comparison with the theory of charge-density waves in this material. In 2H-TaSe/sub 2/ the normal to incommensurate phase transition was found to be second order; the incommensurate to commensurate transition was first order. Specific-heat measurements on this material indicate that the zero-temperature coherence length is relatively short; ..pi..xi/sub 0/ approx. = 14 A. The resistivity of 2H-TaSe/sub 2/ immediately above the normal to incommensurate phase transition is dominated by resistive scattering from the periodic structural deformations accompanying the charge-density waves. The specific-heat and resistivity measurements both indicate that the normal to incommensurate phase transition in 2H-TaSe/sub 2/ can be analyzed within a nearly-mean-field model.

• Research Organization: IBM Thomas J. Watson Research Center, Yorktown Heights, New York 10598
• OSTI ID: 5242924
• Journal Information: Phys. Rev., B; (United States), Vol. 16:10
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
TANTALUM SELENIDES
CRYSTAL-PHASE TRANSFORMATIONS
ELECTRIC CONDUCTIVITY
SPECIFIC HEAT
TANTALUM SULFIDES
NEUTRON DIFFRACTION
CHALCOGENIDES
COHERENT SCATTERING
DIFFRACTION
ELECTRICAL PROPERTIES
PHASE TRANSFORMATIONS
PHYSICAL PROPERTIES
SCATTERING
SELENIDES
SELENIUM COMPOUNDS
SULFIDES
SULFUR COMPOUNDS
TANTALUM COMPOUNDS
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENT COMPOUNDS
360602* - Other Materials- Structure & Phase Studies
360603 - Materials- Properties