Preferential site occupation and magnetic structure of Nd2(Co<i>x</i>Fe1−<i>x</i>)14B systems

Abstract

Rietveld analyses of room-temperature neutron diffraction data for seven Nd2(CoxFe1−x)14B alloys (x=0, 0.1, 0.3, 0.5, 0.7, 0.9, 1) are reported. Throughout the entire composition range the Nd2Fe14B-type tetragonal crystal structure is maintained, with the lattice constants decreasing significantly as the Co concentration x increases. We find that the j2-type transition-metal sites are preferentially occupied by Fe ions in the pseudoternary systems, a result which is analogous to the preferential Fe occupation of c sites we previously observed in hexagonal Nd2(CoxFe1−x)17 alloys.