TRANSVERSE MAGNETORESISTANCE OF ALUMINUM

Because Al shows promise as a conductor suitable for a cryogenic magnet, its transverse magnetoresistance was studied. The measurements were made on six samples of 99.999 percent pure aluminum at 4.2 K in magnetic fields H up to 120,000 gauss, the samples having been annealed, and in two cases cold worked, so as to be in various states of strain. Valid data were obtained from four of the samples, for which the ratios (at H O) of room temperature resistivity R(300 K) to the resistivity R at 4.2 K were 1530, 1180, 1075, and 333. Almost all of the resistivity decrease gained at H O by using a less strained metal is preserved at high magnetic fields for a metal whose magnetoresistance exhibits a predominately saturating behavior. The data from the 4 samples were normalized fairly well by Kohler's rule. This indicates that further reductions in the power necessary to operate cryogenic magnets can be profitably achieved by using purer Al.