Method for making a high purity aluminum conductor used at ultra low temperature

Abstract

The aluminum conductor having increase of its electric resistivity kept small at ultra low temperature of 30° K. or lower even after cyclic strain is given at ultra low temperature, by controlling the crystal structure of the high purity aluminum conductor with purity of 99.9-99.9999 wt % so as to consist of (i) a veritable single or a substantially single crystal consisting of a bundle of sub-grains which have their crystal axes in the same direction or in the directions within a couple of degrees of deviation as a whole which has a specific crystal axis of or or the crystal axes close thereto in the longitudinal direction of the aluminum conductor, or (ii) a polycrystal most of which grains have respective specific crystal axes of and/or , or the crystal axes close thereto with respect to each grain in the longitudinal direction of the aluminum conductor, and have specific grain size of 0.01 mm to 3.0 mm.