Authors: Gary S Collins
Publish Date: 2007/01/09
Volume: 42, Issue: 6, Pages: 1915-1919
Abstract
Phases having compositional fields narrower than about 1 at and appearing as lines in binary phase diagrams often are assumed to have properties independent of composition That such an assumption can be seriously in error is illustrated by recent measurements on pairs of samples prepared to have compositions at opposing phase boundaries Two microscopic properties lattice locations of highly dilute solutes and diffusional jump frequencies were studied respectively through measurement of static and dynamic nuclear quadrupole interactions using the method of perturbed angular correlation of gamma rays PAC At opposing boundary compositions PAC probe atoms have been observed to occupy different lattice sites or to have jump frequencies differing by a factor of 100 Such gross differences suggest measurements of other properties of line compounds should be made on pairs of samples having the opposing boundary compositions in order to avoid inconsistent or unreproducible resultsI thank Aurélie Favrot Li Kang Egbert Rein Nieuwenhuis Denys Solodovnikov Jipeng Wang and especially Matthew O Zacate who contributed significantly to the measurements and analysis This work was supported in part by the National Science Foundation under Grants DMR 0091681 and 0504843 Metals Program
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