Mössbauer effect study ofCu2MnAl1−xSnxcompounds

Abstract

Results of a M\"ossbauer effect study of a range of ${\mathrm{Cu}}_{2}\mathrm{Mn}{\mathrm{Al}}_{1\ensuremath{-}x}{\mathrm{Sn}}_{x}$ compounds are presented for $x=0.05, 0.10, 0.15, 0.25, 0.50, \mathrm{and} 0.75$. The hyperfine magnetic field at Sn nuclei is proportional to a number of Sn atoms substituted for Al ones and it increases by \ensuremath{\sim} 17 kOe per Sn atom. It does not depend, however, on tin concentration in the compound. This reflects a well-localized character of ferromagnetism in these compounds. The coexistence of the different fields for a given sample cannot be explained either by the Blandin-Campbell model or by the Jena-Geldart one. The results and their interpretation were supported by fitting the M\"ossbauer spectra of the alloys studied with another independent method which gave the distributions as well as the average magnetic fields. The isomer shift also depends on how many Sn atoms have been substituted for Al ones, and it decreases on average by 0.09 mm/s per Sn atom.