Crystallographic parameters of magnetic Pr2Fe14−xCoxB-type alloys determined using anomalous x-ray diffraction with synchrotron radiation

Abstract

Anomalous x-ray synchrotron diffraction was used to determine the crystallographic parameters of PrFeCoBbased magnetic alloys. The effect of cobalt concentration on the crystallographic parameters of the magnetically hard Pr2Fe14−xCoxB phase was studied. The results indicate that addition of cobalt has a marked effect on crystal structure. Variation of the c parameter decreased twice as much as the a parameter with increase in Co content. The positions of inequivalent atoms of the magnetically hard matrix phase ϕ in the Pr-based alloys were determined using Rietveld refinement. This permitted determination of the relative distance of each inequivalent atom from its nearest neighbors. Cobalt occupied the 16k2 site and Fe had a tendency to occupy the 8j2 sites located between the Kagomé layers.