High pressure study of the antiferromagnetic state of chromium alloys

We have studied the pressure dependence of the Néel temperature (TN) in Cr-Si, Cr-Ge, and Cr-Sn alloys. In all alloys we have found a transition to the commensurate antiferromagnetic spin density wave state above a certain threshold concentration (1·35at.% Si, 0·6at. % Ge, and >2 at.% Sn). On the basis of a two-band nesting model this behaviour can be understood only if the group IV elements act as electron donors to the d band of Cr, as is found for transition metal additions.