J. Phys. F: Metal Phys., lO(1980) L293-8. Printed in Great Britain LETTER TO THE EDITOR Chemical ordering in Y66(Fe,Mnl-x)34 metallic glasses

Abstract. The compositional dependence of the 57Fe Mossbauer effect spectra for the metallic glasses Y66(Fe,Mnl has been studied. For high concentrations of Fe the spectra consist of two symmetric peaks with the spectra becoming progressively more complex as the Fe content decreases. The smooth variation of the parameters derived from the spectra indicates that Fe and Mn perform the same functions in the glass. We find evidence for chemical ordering in these glasses and we demonstrate the existence of two distinct atomic sites for Fe. Site I we attribute to Fe atoms having predominately Y near neighbours and site 2 is identified as Fe atoms having a larger number of Fe (Mnj near neighbours. The nature and extent of the short-range order in metallic glasses is currently of great interest. Many techniques have been used to study the structure of these glasses (x-ray, neutron, electron scattering, EXAFS). These techniques can provide radial information on the average coordination number and average interatomic spacings. In metal-metalloid glasses (e.g. Pd80Si20) evidence for chemical ordering has been found. For the glasses CO-P (Bletry and Sadoc 1975), PdssSi16 (Sadoc and Dixmier 1977) an