Transmission electron microscopy study of large field induced anisotropy (Co1−xFex)89Zr7B4 nanocomposite ribbons with dilute Fe-contents

In-situ investigation of phase formation in nanocrystalline (Co97.5Fe2.5)89Zr7B4 alloy by high temperature x-ray diffraction

“…This is consistent with observations in prior work for this alloy system. [3][4][5][6][7][8] At 600 C a broad peak at 47.0 suggests crystallites with hcp stacking rather than fcc. As temperature is further increased this peak disappears at the expense of continued growth of the corresponding fcc peaks up to 700 C. Peaks due to a secondary crystalline phase, typically (Co,Fe) 23 Zr 6 or (Co,Fe) 2 Zr, 3 do not appear in the high temperature XRD patterns obtained here.…”

“…Recent suppression of the nucleation of the c-phase has been observed in Co-Fe-based nanocomposites at compositions where the binary Fe-Co phase diagram predict that the a-andcphases coexist. [3][4][5][6][7][8] In Fe-Ni-based nanocomposites, similar observations in Fe-rich alloys 11 show nucleation of the c-phase is suppressed in favor of a metastable a-phase.…”

“…2 Fe-based alloys have attracted the most attention, as optimized alloys exhibit relatively high magnetic flux densities and low losses. Co-based alloys, with small or zero magnetostriction, a relatively large response to magnetic field annealing [3][4][5][6][7][8] and excellent mechanical properties making them interesting for magnetic sensors and high frequency applications. 9,10 In transforming amorphous precursors to nanocomposite magnets, it is possible to suppress stable phase formation and exploit properties of metastable phases.…”

“…In the context of classical nucleation theory, previous work postulated that preferential nucleation of bcc crystallites in Co-rich alloys could be potentially explained in terms of strain and/or interfacial energy effects. [5][6][7] The possibility of hcp phase formation arises from similar free energies of the hcp and fcc phases and, in some cases, it is difficult to unambiguously identify grains as hcp or fcc because of a high density of stacking faults.…”

Tuning of Magnetic Properties and Domain Structure in Feco- and Fesi-Based Soft Magnetic Alloys by Thermal Processing Under Magnetic Field

“…Although, most of the research on magnetic annealing has been devoted to the various binary and ternary alloys of Fe, Co, and Ni, the effects of field annealing were found to be present also in the alloy systems with only one kind of magnetic atoms such as silicon steel sheets [6] and more recently developed Fe-Cu-Nb-B-Si [7] and Co-(Zr,Nb)-B-Cu nanocrystalline alloys [8,9]. Here, an important role in development of the field-annealing induced anisotropy seems to be played by metalloid atoms and other mobile minority atoms/defects species.…”