MOSSBAUER-EFFECT STUDY OF NONDIMENSIONAL AND 2-DIMENSIONAL QUASI-CRYSTALLINE ALLOYS IN THE AL-PD-FE SYSTEM

Room temperature Fe-57 Mossbauer effect measurements of the one- and t wo-dimensional quasicrystalline phases of Al75Pd15Fe10 are reported. B oth materials show Mossbauer spectra with asymmetric doublets which ha ve been analyzed in terms of a distribution of quadrupole splittings, and in terms of a discrete expansion of quadrupole splittings. The one -dimensional material shows the following characteristics compared wit h the two-dimensional material; (1) a larger mean quadrupole splitting , (2) a more positive mean isomer shift and (3) a broader distribution of quadrupole splittings. These results indicate that the local Fe en vironments in the one-dimensional material are less isotropic than in the two-dimensional material and that this material is characterized b y a higher concentration of open volume defects.