Physical contributions to the heat capacity of nickel

• Published in: The Journal of physics and chemistry of solids Vol. 42; no. 9; pp. 861 - 871
• Main Authors: Meschter, Peter J., Wright, James W., Brooks, Charlie R., Kollie, Thomas G.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 1981
• ISSN: 0022-3697; 1879-2553
• DOI: 10.1016/0022-3697(81)90174-8

Heat capacity data for solid nickel have been re-evaluated and analyzed into physical contributions, 0–1726 K. Two new sets of measurements of C p (Ni), 333–1500 K, have been combined with literature data to produce an evaluated data set with uncertainty ⩽ ± 2%. These smoothed data have been analyzed into vibrational harmonic, electronic, magnetic and dilatational contributions with the aid of auxiliary measurements of expansion coefficient, compressibility, vibrational and electronic densities of states, elastic constants, and magnetic exchange integral and susceptibility obtained from the literature. The vibrational harmonic term is interpreted in terms of a θ D -vs- T curve in accord with predictions of the density-of-states distribution. The electronic contribution is smaller than predicted by free-electron theory due to a large electron-phonon effect. The electronic term for paramagnetic nickel is in good agreement with that predicted from band calculations. The magnetic contribution yields a magnetic entropy in accord with theoretical predictions, and a magnetic internal energy and critical-point behavior in agreement with the isotropic Heisenberg model. The experimental heat capacity can be accounted for without reference to vibrational anharmonic and vacancy contributions, in accord with recent calculations.