ELECTRICAL RESISTIVITY OF GOLD-CHROMIUM ALLOYS WITH HIGH CONCENTRATION OF CHROMIUM

The electrical resistivity and the magnetic susceptibility of Au-Cr alloys with high concentration of chromium up to 26 atomic percent have been measured from 4 to 1000°K. The electrical resistivity shows no sharp anomaly but a broad peak above the Neel temperature. In the paramagnetic region, the resistivity decreases with increasing temperature. In order to analyze this anomalous temperature dependence of the resistivity, the magnetic part of the resistivity was estimated by subtracting the resistivity of gold as a phonon contribution from the observed one. It was found that the magnetic resistivity is proportional to —c log T, where c is the chromium concentration and T the temperature. This result seems to be explaind by an extended Kondo effect. On the other hand, a modification of Blatt's theory is also discussed to explain the decrease of the resistivity. A similar decrease in the resistivity with temperature in several noble metal alloys with high concentration of 3d metals and in other alloys containing magnetic atoms with high concentration is also described. © 1969, THE PHYSICAL SOCIETY OF JAPAN. All rights reserved.