Magnetic Susceptibility of Dilute Alloys of Nickel in Copper between 2.5°K and 295°K

Abstract

The magnetic susceptibilities of pure Cu and dilute Cu—Ni alloys containing 0.59, 1.16, and 2.48 atomic percent Ni have been measured by a Gouy method at temperatures between 295°K and 2.5°K. At room temperature all the alloys were found to be diamagnetic, the numerical value of the susceptibility decreasing with increasing nickel content, as found by earlier workers. The paramagnetic contributions found at low temperatures were, however, considerably smaller than those previously reported, although the 2.48% alloy was paramagnetic at temperatures below 16°K. The resultant susceptibility of each alloy is given with reasonable accuracy by an expression of the form $aT+b+\left(\frac{c}{T}\right)$, and the significance of each of these terms is discussed. A theoretical model, in which the number of nickel atoms possessing resultant magnetic moments is temperature-dependent and which fitted the earlier high-temperature data reasonably well, has been found inadequate for the new low-temperature results.