Transport Properties of the Ferromagnetic Metals. I. Cobalt

Abstract

The thermal conductivity, electrical resistivity, and thermoelectric power of well-characterized, polycrystalline specimens of pure Co have been determined in the temperature range of 90 to 1250 K. Additionally, the measurements of the electrical resistivity have been extended to 1750 K, and the coefficient of thermal expansion measured between 300 and 770 K. The new results are compared with those previously published, and, for the low temperature h.c.p. phase, compared with predictions based on published band structure calculations. Qualitatively, the observed results agree with the predictions, particularly as far as the very unusual temperature variation of the Lorenz function is concerned; quantitative comparisons, however, are impossible, due to the lack of precision in the calculated band structures. The theoretical analysis of the results for the high temperature f.c.c. phase will be given together with that of Ni in Part II.