Electrical Resistivity Studies of Chromium-Rich Chromium-Cobalt Alloys

The electrical resistivity of chromium-cobalt alloys, containing 0.4, 1.2, 1.7, 2.2, 2.7, 3.5, 4.4, 6.2, and 8.0 at.% cobalt, has been studied as a function of absolute temperature from 4 to 350^∘{}K. The N\'eel point first decreases with increasing cobalt concentration, reaching a minimum at about 1.2 at.% cobalt, then increases to a maximum value at 2.7 at.% cobalt, and then gradually decreases again. At low temperatures the alloys containing more than 2.7 at.% cobalt exhibit a minimum in the resistivity versus temperature plot. This is the first time this phenomenon has been noticed in chromium solid solutions; it appears to have essentially the same origin as in certain other magnetically dilute solid solutions. Electrical magnetoresistivities of the above-mentioned chromium-cobalt alloys have been studied in transverse magnetic fields up to 12 kOe and longitudinal fields up to 60 kOe at 4.2^∘{}K. These fields have small influence on the electrical resistivity, which is in sharp contrast with the behavior found in chromium-iron alloys. These results are briefly discussed from the viewpoint of recent theories.