English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Zendy Plus

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Zendy Tools

Zendy Open

This paper addresses the time-dependent crystallization process occurring in “bulk” amorphous Co80−xFexB20 (x = 20, 40) metallic ribbons by means of synchrotron x-ray diffraction (SXRD) and transmission electron microscopy. Metallic ribbons, produced via melt-spinning technique, were annealed in-situ, with SXRD patterns collected every 60 s. SXRD reveals that Co40Fe40B20 alloys crystallize from an amorphous structure to a primary bcc α-(Co,Fe) phase, whereas Co60Fe20B20 initially crystallizes into the same bcc α-(Co,Fe) but exhibits cooperative growth of both stable and metastable boride phases later into the hold. Johnson-Mehl-Avrami-Kolmogorov statistics was used on post annealed samples to determine the mechanisms of growth and the activation energy (Ea ) of the α-(Co,Fe) phase. Results indicate that the growth mechanisms are similar for both alloy compositions for all annealing temperatures, with the Avrami exponent of n = 1.51(1) and 2.02(6) for x = 20 and 40, respectively, suggesting one-dimensional growth, with a decreasing nucleation rate. Activation energy for α-(Co,Fe) was determined to be 2.7(1) eV and 2.4(3) eV in x = 20 and 40, respectively, suggesting that those alloys with a lower Co content have a stronger resistance to crystallization. Based on these results, fabrication of CoFeB magnetic tunnel junctions via depositing amorphous layers and subsequently annealing to induce lattice matching presents itself as a viable and efficient method, for increasing the giant magnetoresistance in magnetic tunnel junctions.

Time-resolved synchrotron x-ray diffraction studies of the crystallization of amorphous Co(80−x)FexB20