Determination of Interstitial Sites for Localized Diffusion from Interference of MössbauerγRadiation

Abstract

By Mossbauer spectroscopy, the anisotropy of recoilless y radiation emitted from a jumping atom is observed. The set of interstitial sites is determined for localized diffusion of Fe in an interstitial cage in Al. From the temperature dependence of the broadening of the Mossbauer resonance 18 (±1) meV is obtained for the activation energy of this process.

A channeling study of vacancy – solute atom complexes in irradiated aluminum crystals

“…Unfortunately, in the present case, the combination of [7] and [4] gives Ci coefficients that are almost identical to those of [3]. Similarly, the use of [6] does not provide an independent equation for the calculation of Ci. There remain three equations in four unknowns, so it is necessary to make some assumptions concerning the random fraction CR of solute atoms.…”

“…It is formed when a self-interstitial atom is trapped strongly by a small solute atom; e.g., a Zn solute atom bound to an A1 atom, which has also been observed by internal friction measurements (21). A similar defect complex with Fe solute atoms has been observed by the Mossbauer effect (5,6).…”

“…Several methods, including ion channeling ( 1 -4), the Mossbauer effect (5,6), perturbed angular correlation (PAC) (7-lo), internal friction ( 1 I), field ion microscopy (12), positron annihilation ( 13,14), diffuse X-ray scattering ( 15,16), and electrical resistivity (17)(18)(19), have been used to study the trapping of vacancies and self-interstitials by solute atoms in metals. Many of these methods have the potential to determine defect configurations, although it is sometimes difficult to identify a specific configuration when several trapping configurations are present.…”

“…Many of these methods have the potential to determine defect configurations, although it is sometimes difficult to identify a specific configuration when several trapping configurations are present. In techniques such as the Mossbauer effect (5,6) and PAC (7-lo), the electronic environments of specific solute atoms are labeled, and by inference or by a selective introduction technique (e.g., quenched-in vacancies) the trapped defect is identified. By ion channeling (1-4), the actual lattice positions of selected solute atoms are determined after they have trapped lattice defects.…”

Direct and Indirect Methods of the Analysis of Interatomic Interaction and Kinetics of a Relaxation of the Short-Range Order in Close-Packed Substitutional (Interstitial) Solid Solutions

“…Експериментально також спостерігались (наприклад, в [258][259][260][261][262][263][264][265]) різкі кутові залежності мессбауерівських (і нейтронних) спектрів монокристалів. Слід зазначити, що треба врахо-вувати кореляцію між послідовними дифузійними стрибками атомів, яка завжди проявляється при вакансійному механізмі дифузії [266]: на-віть якщо атом може перейти лише до сусідньої вакансії, вона не відра-зу віддаляється від дифундуючого атома, і в результаті можливих декі-лькох послідовних стрибків атома до цієї вакансії ймовірності атомних стрибків до більш віддалених сусідів стануть відмінними від нуля.…”