Temperature Dependence of the Electrical Resistivity of Pure Iron at Low Temperatures

Abstract

The temperature dependence of electrical resistivity has been measured for pure iron with various RRRH,4.2K values from 352 to 11390. It is found that the experimental data in the temperature range from 1.6 K to room temperature can be expressed by a simple sum of the phonon scattering term, a term proportional to T2 and residual resistivity. The phonon scattering term is estimated by the Grüneisen-formula. The coefficient of the T2 term is (2.2±0.1)×10−11(Ω·cm·deg−2) and the term proportional to T is negligibly small. A new index, RRRH,0K, is suggested as an appropriate measure of purity for highly purified iron, and the largest value of RRRH,0K obtained is 20210 on the sample with RRRH,4.2K 11390.