Influence of interstitial Mn on local structure and magnetism inMn1+δSb

Joshua A. Kurzman, Andrew J. Martinolich, James R. Neilson
2015 Physical Review B  
We report x-ray total scattering and pair distribution function (PDF) studies of the structural relaxation around interstitial manganese (Mn_i) in ferromagnetic Mn_1+δSb (0.03 <δ< 0.23) alloys, guided by density functional theory (DFT). Refinements to the experimental PDF using a crystallographically constrained structural model indicate an expansion in the equatorial plane of the Mn_iSb_5 trigonal bipyramidal site, which introduces significant positional disorder in addition to the
more » ... ndom occupation of interstitial voids. Observation of a weak diffuse signal near the symmetry-forbidden (001) reflection position is indicative of correlated disorder from the clustering of Mn_i. Density functional relaxation of supercells approximating the δ = 0.08, 0.15, and 0.23 compositions provides improved models that accurately describe the short-range structural distortions captured in the PDFs. Such structural relaxation increases the DFT calculated moment on Mn_i, which aligns antiparallel to the primary Mn moments, but leads to insubstantial changes in the average Mn and Sb moments and moments of Mn and Sb proximal to interstitials, thus providing a more accurate description of the observed bulk magnetic properties.
doi:10.1103/physrevb.92.184414 fatcat:ki5gf7sn2fgptg6e443cb7npoi