Electrical resistivity of La

Abstract

The electrical resistivity of high-purity double hexagonal-close-packed (dhcp) $\ensuremath{\alpha}\ensuremath{-}\mathrm{La}$ from 5 to 300 K is reported. Measurements were made on small-grained samples prepared by heat treatment of eold-worked lanthanum. Measurements were also made on samples cut in different directions from an ingot slowly cooled from the molten state. The room-temperature results were all within 2% of the mean value. Chemically pure $\ensuremath{\beta}\ensuremath{-}\mathrm{La}$ (fcc) cannot be retained at room temperature, hence, measurements were made on an fcc sample of La containing 0.2-at.% Gd and \ensuremath{\sim} 0.8-at.% total interstitial nonmetallic impurities. The cubic form has almost the same type of temperature dependence as the dhcp form, but has a 10% lower magnitude.