57Fe Mössbauer effect studies in Y66(FExTM1−x)34 metallic glasses

⁵⁷Fe Mössbauer effect (ME) measurements in a variety of Y based metallic glasses are reported. The spectra are best described in terms of a model which assumes two Fe sites having nearly equal intensities. We find that the ME parameters are smooth and monotonic functions of composition (x) for the glasses Y₆₆(Fe_xTM_1?x)₃₄ (TM = Mn, Fe, Co, Ni, Cu Zn) leading to the conclusion that Fe randomly substitutes for the various TM in these glasses. The nature of the two sites we observe is radically different depending on whether TM is to the right or left of Ni. Those glasses containing Mn, Fe, Co, and Ni display a degree of chemical ordering. In these glasses (TM = Mn, Fe, Co, Ni) we identify site 1 as a Y-dominated Fe environment and site 2 as an Fe environment having a larger number of Fe(TM) near neighbors. A correlation between the isomer shifts IS] of site 2 and Fe impurities in the corresponding crystalline compounds PTYM₂ is noted and discussed in terms of a volume dependence of IS.