The local structure from two experimental atomic probes: EXAFS and Mِssbauer spectroscopies

The aim of the present study is to determine the correlations between two experimental atomic probes used to investigate the structure of disordered solids: the extended X-ray absorption fine structure (EXAFS) and the Mössbauer spectroscopy (MS). The study has been performed in a series of metallic glasses of composition (FexCo1−x)80B20 (x=0.06, 0.1, 0.2, 0.35, 0.5, 0.80, 1). The EXAFS spectroscopy on the Fe and the Co K-edge has been used to determine the local structure and its changes with composition. From the 57Fe MS we have obtained the hyperfine parameters: isomer shift (IS), hyperfine fields, and its standard deviation at the Fe nuclei. We have established that the IS is correlated with the distance between Fe or Co and their first neighbour metallic atoms (RFe–M and RCo–M) and the standard deviation of hyperfine field distribution is due to the disorder of interatomic distances inside the first coordination shell of Fe.