Magnetic susceptibility and antiferromagnetism of dilute chromium‐osmium alloys

The magnetic susceptibility χ of Cr–Os alloys containing 0.3, 0.6, 1.1, and 2.0 at.% Os has been measured as a function of temperature T between 4.2 and 600 K. The χ vs T curves exhibit a well defined knee at the Neel temperature TN. TN increases with Os content, in agreement with earlier determinations from electrical resistivity data. at the Neel temperature TN. TN increases with Os content, in agreenment with earlier determinations from electrical resistivity data. The rise of TN is consistent with expectations based on the rigid band model for these alloys. The measured susceptibility in the antiferromagnetic regime below TN is compared with that calculated using the two‐band model for chromium. Variation in the size of the electron jack and hole octahedron upon alloying is taken into account within the rigid band approximation. The impurity and phonon‐scattering contributions to the susceptibility have been included. Agreement between theory and experiment is good over most of the temperature range, ...