Chinese Acad Sci, Inst Phys, State Key Lab Magnetism, Beijing 100080, Peoples R China
; Chinese Acad Sci, Inst High Energy Phys, Beijing 100049, Peoples R China
In this paper neutron diffraction experiments were performed for Fe-substituted Mn-12 in order to determine the sites of Fe atoms. The results of structure refinements for the sample with our accessed highest Fe content showed that all Fe atoms occupied Mn(3) sites in the Mn-12 skeleton. The x-ray absorption. ne structure experiments as well as multiple scattering simulations gave the same result. Thus we concluded that Fe atoms only occupied Mn( 3) sites. This conclusion also means that Fe-substituted Mn-12 series only includes the four single-molecule magnets of [Mn(12-x)FexO(12)(CH3COO)(16)(H2O)(4)] center dot 2CH(3)COOH center dot 4H(2)O (x = 1, 2, 3, and 4), denoted by Mn11Fe1, Mn10Fe2, Mn9Fe3, and Mn8Fe4, respectively.