RMn6Sn6compounds(R=Mg,Zr, and Hf) studied by119SnMössbauer spectroscopy and band structure calculations

Abstract

The $R{\mathrm{Mn}}_{6}{\mathrm{Sn}}_{6}$ compounds $(R=\mathrm{Mg},$ Zr, and Hf) of ${\mathrm{HfFe}}_{6}{\mathrm{Ge}}_{6}$-type structure were investigated by ${}^{119}\mathrm{Sn}$ M\"ossbauer spectroscopy and first-principles electronic structure calculations based on the Korringa-Kohn-Rostoker method in a nonrelativistic approach. The purpose of this study was to gain information on the electronic and magnetic properties of these materials with an emphasis on the hyperfine fields transferred on the nucleus of the three crystallographically inequivalent tin atoms. These huge hyperfine fields (as large as 33 T) are found to be independent of the R metal valence. The calculations indicate that the hyperfine fields are negative (with respect to the Mn magnetic moment) and good agreement with experiment is found. The chemical bonding is discussed based on the l-decomposed site projected densities of states. The theoretical results also provide interesting predictions to be confirmed by future transport and photoemission experiments.