Atomic rearrangements during structural relaxation inFe78Si9

Abstract

Structural relaxation in a magnetic metallic glass having composition Fe78Si9B» has been studied using Mossbauer spectroscopy. Information about the atomic-level changes occurring in the specimen has been obtained through the correlated distributions of the hyperfine-interaction parameters. Increasing annealing temperature causes a decrease in the geometrical distortions as well as a change in topological short-range order. These changes involve (i) a decrease in the average interatomic spacing, and (ii) topological rearrangement of atoms resulting in significant changes in the population of transition-metal sites with different numbers of metalloid near neighbors.

Preparation of Nanocrystalline Alloy by Devitrification

“…It is supported by the enhanced mean hyperfine field (MHF) on Möss-bauer spectroscopy (Table 1). [22] Secondly, according to the Mullins±Sekerka theory, [18] growth of these crystals into dendrites may be understood in terms of nucleation of b.c.c. Fecrystals with interfacial instability.…”

On the microstructural origin of stress-induced anisotropy in Co67Fe4Mo1.5Si16.5B11 metallic glass

“…These results, in conjunction with those of XRD measurements, suggest that chemical short-range order increases in both the samples, while the topological short-range order shows a decrease in the stress-annealed samples. Furthermore, the isomer shift in metallic glasses depends mainly upon the average number of the metalloid near neighbors and their distances [11], and thus is sensitive to the short-range order of metalloid around the Fe-atom A decrease in the Fe-metalloid distance or an increase in the metalloid near neighbors results in a decrease in the isomer shift [11]. In the present case, since Co is the main constituent, any change in the shortrange order of Co atoms around Fe atoms would also cause Fe isomer shift to change.…”

“…ossbauer measurements give information about both, chemical and topological short-range order, XRD technique is predominantly sensitive to the topological short-range order in the system [10][11][12][13]. Information about the magnetic anisotropy is obtained from both M .…”

On the structural relaxation of Fe65Gd5 Cr10B20 amorphous alloys

“…Irreversible changes are attributed to a decrease of the free volume by the disappearance of voids, resulting in an increase in topological short-range order (TSRO), while reversible changes are the result of changes in chemical or compositional short-range order (CSRO). Three possible rearrangements can be associated with structural relaxation [6]: (i) a change in the mean near-neighbour distance, (ii) a change in the mean chemical order, and (iii) a change in the mean coordination number. E-mail addresses: izaharie@gmail.com, ioan.zaharie@fiz.upt.ro.…”