Electrical resistivity and thermoelectric power of polycrystalline uranium at elevated temperatures

Abstract

The electrical resistivity, ϱ( T), of high purity uranium [ ϱ(3.67 °K) = 0.955 μΩcm] has been studied as a function of temperature, T, between 295 and 1370 °K. Measurements also have been made on the absolute thermoelectric power, S u ( T), between 380 and 1000 °K. The uranium used in this study is the same as that previously studied between 2 and 300 °K. The crystal structure changes taking place at elevated temperatures cause anomalies in the ϱ( T) vs. T and S u( T) vs. T curves. The agreement between the ϱ( T) data of different investigators is better for the α phase than for the β and γ phases. Large disagreements in S u ( T) among different investigations exist at elevated temperatures. The S u ( T) vs. T curve of the present study joins smoothly the curve between 20 and 300 °K due to Meaden and Lee. The abovementioned electrical transport properties are briefly discussed from the viewpoint of the electronic structure of uranium and the multiband conduction theory.