Electrical Resistance of Pure Aluminium at Liquid Helium Temperatures

Abstract

THE electrical resistance of aluminium at liquid helium temperatures has been investigated by Tuyn and Kamerlingh Onnes¹, by Meissner and Voigt², and by Keesom³, who discovered that this metal becomes supra-conducting at about 1.14°K. The measurements of Meissner and Voigt appear to show that the resistance of aluminium in the liquid helium region between 4.2° and 1.3° K. is not constant, but increases slightly with decreasing temperature. On the other hand, Tuyn and Kamerlingh Onnes, as well as Keesom, have found that the resistance is constant in this region, but examination of their data shows that the residual resistance of their specimens was larger than those of Meissner and Voigt. A slight increase of resistance at liquid helium temperatures has also been reported for molybdenum, cobalt and magnesium², and recently for gold⁴. Since such a phenomenon is of considerable theoretical interest, and since we had at our disposal some samples of very pure aluminium, we have made further measurements on the resistance of this metal at liquid helium temperatures.