Doctor of Philosophy (Ph.D.)
Amorphous alloys of VAl and VSi have been prepared by a process of r.f. sputtering onto cryogenic substrates. The Nuclear Magnetic Resonance has been examined in an effort to understand how the electronic structure of these amorphous alloys compares to that of the corresponding crystalline alloys, and to extend the study of the electronic properties of these alloy systems into composition ranges where the crystalline alloys do not exist, because of solubility limits.;The Al('27) and V('51) Knight shifts were measured at 77(DEGREES)K and 300(DEGREES)K, for Al concentrations extending from 15 to 85 atomic percent, in amorphous VAl. The results are found not only to agree with those of the crystalline alloys below 40 atomic percent Al (the solubility limit), but to extend the crystalline behavior right into the region of immiscibility. In amorphous VSi only the V('51) Knight shift was measured. The V('51) Knight shift, before annealing, was found to be nearly constant with both temperature and alloy composition. After annealing the amorphous VSi alloys, however, a strong temperature dependence was observed in the V('51) shift, probably due to the formation of the compound V(,3)Si upon crystallization.;These results are explained in terms of a model which treats the amorphous alloys as though they were crystalline but with an extended solubility range. The case of V(,3)Si is considered as an exception due to its peculiar crystal structure and resulting electronic behavior.;The V('51) NMR linewidths were also measured in both amorphous VAl and amorphous VSi. These are discussed in terms of the short range order found in the amorphous alloys.
© The Author
Mattix, Larry, "NMR in amorphous vanadium alloys" (1981). Dissertations, Theses, and Masters Projects. Paper 1539623725.