| Time-of-flight inelastic neutron scattering and Raman measurements were performed on amorphous (a-) metals. The neutron weighted vibrational density of states, G(E), obtained for a-Fe(,78)P(,22), a-Ni(,82)B(,18) and a-Ni(,67)B(,33) transition metal-metalloid alloys (TM-m), indicated two major vibrational bands: a low frequency acoustic-like band and a high frequency optic-like band which are derived from TM-TM and TM-m interactions, respectively. Similar neutron measurements were performed on the corresponding polycrystalline (c-) alloys, c-Fe(,3)P and c-Ni(,2)B.; A comparison of the amorphous and crystalline densities of states indicates the elimination of sharp features and the addition of vibrational states at low and high frequencies upon amorphization. The experimental G(E) results for a-Fe(,78)P(,22) are in good agreement with the theoretically predicted spectrum. Differences in peak positions are attributed to weaker Fe-Fe and Fe-P interaction strengths. The results are consistent with similar shortrange order in the amorphous and crystalline systems.; A comparison between the a-Ni(,67)B(,33) and the phenomenologically broadened c-Ni(,2)B spectrum indicates a change in the short-range order. This finding is consistent with structural measurements on this alloy. The results for the Fe-P and Ni-B systems indicate an increase in the TM-m bonds strength for the Fe-P alloy, suggesting a greater degree of covalency in that system.; Raman measurements were carried out using interference enhanced Raman Spectroscopy (IERS) on thin film Ni-B alloys. The measured spectra provide information about the weighted phonon density of states, and is in good agreement with the neutron results. This first observation of Raman scattering from an amorphous metal implies that the study of thin film noncrystalline metals is now feasible. |
