SUPERCONDUCTING AND NORMAL SPECIFIC HEATS OF NIOBIUM

Journal Article · Sat Sep 01 00:00:00 EDT 1962 · Physical Review (U.S.) Superseded in part by Phys. Rev. A, Phys. Rev. B: Solid State, Phys. Rev. C, and Phys. Rev. D

DOI:https://doi.org/10.1103/PhysRev.127.1501· OSTI ID:4773622

Hirshfeld, A T; Leupold, H A; Boorse, H A

Measurements reported are undertaken to determine the -low- temperature heat capacity of niobium and to determine the effect of high- temperature annealing (2340 deg C) and degassing on a sample. The measurements cover the temperature interval 1.1 to 11.5 deg K and are significantly different from those obtained prior to the thermal treatment. The normal-phase heat capacity may be expressed by the usual relation, C/sub n/= gamma T + const (T/ THETA /sub D/)/sup 3/, with gamma = (7.53 PP 2%) mJ/mole deg/sup 2/ and THETA / sub D/ = 238 deg K plus or minus 1.5%. The zero-field transition temperature, determined from the midpoint of the transition interval, is found to be 9.09 deg K. In the superconducting phase below 1.7 deg K, the total heat capacity C/sub s/ , is found to be less than the lattice specific heat alone in the normal phase. This anomalous result is comparable to that found in indium. This anomaly complicates the determination of the superconducting electronic specific heat C/ sub es/, but it may be evaluated to give a gamma T/sub c/ exp (--bT/sub c//T), with a = 12.6 and b = 1.71. (auth)

• Research Organization: Columbia Univ., New York
• NSA Number: NSA-16-033627
• OSTI ID: 4773622
• Journal Information: Physical Review (U.S.) Superseded in part by Phys. Rev. A, Phys. Rev. B: Solid State, Phys. Rev. C, and Phys. Rev. D, Journal Name: Physical Review (U.S.) Superseded in part by Phys. Rev. A, Phys. Rev. B: Solid State, Phys. Rev. C, and Phys. Rev. D Vol. Vol: 127; ISSN PHRVA
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

ANNEALING
LOW TEMPERATURE
MEASURED VALUES
NIOBIUM
PHYSICS
SPECIFIC HEAT
SUPERCONDUCTIVITY