Published online by Cambridge University Press: 21 March 2011
Stimulated by recent experimental observations of room{temperature ferromagnetism of MnxCd1−xGeP2, we investigate the structural, electronic and magnetic properties of these systems as a function of Mn concentration by means of first–principles density-functional-theory-based codes. Moreover, we investigate the effect of the anion substitution (P vs As) in Mn-rich chalcopyirites. Our calculations indicate that the antiferromagnetic alignment is the most stable ordering for all the systems studied, at variance with that experimentally reported. Moreover, we find that there is a slight reduction of the total magnetic moment per Mn atom from ∼5 µB in all the Cd-rich P-based chalcopyrites to ∼4 µB in the Mn–rich MnGeP2 and MnGeAs2 systems.