Thermal behavior, microstructure and magnetic properties of (FexNiyCoz)80B10Si2Cu1Zr7 alloys

Amorphous (FexNiyCoz)(80)B10Si2Cu1Zr7 (x + y + z = 1) alloys were prepared by melt spinning. By investigating the glass-forming ability, thermal behavior, crystallization and magnetic properties of alloy ribbons, detailed and integral pseudoternary diagrams of (FexNiyCoz)(80)B10Si2Cu1Zr7 alloys were con-structed, which can make one clearly understand the effects of ferromagnetic elements (Fe, Co, Ni) on microstructure and physical properties. Results show that, all as-spun alloys show a fully amorphous structure and the coercivity (H-c) can be tuned to a lower value than 45 A/m. After being annealed, alloys with Ni content lower than 64 at.% (y <0.8) show a refined structure of nanocrystals with an average size about 3-14 nm uniformly dispersed in the residual amorphous matrix, and the Fe-rich and Ni-rich alloys exhibit H-c < 155 A/m comparing with the Co-rich alloys (155-416 A/m). No matter as-spun or annealed alloys, (Co + Ni):Fe = 3:7 is the optimal composition to obtain the maximum saturation magnetization (M-s) when y is a certain value in the range of 0-0.2. In addition, alloys in the whole range of composition were classified according to comprehensive magnetic properties of M-s and H-c. The Fe-rich alloys exhibit typical soft magnetic characteristics of simultaneously high M-s and low H-c, as well as high thermal stability of fully amorphous structure or uniform primary crystalline phase + residual amorphous structure. All results give a better insight for amorphous and nanocrystalline (FexNiyCoz)(80)B10Si2Cu1Zr7 alloys to further analyze more efficient magnetic alloys in inductors, transformers, magnetic recording and other magnetic functional materials. (C) 2020 Elsevier B.V. All rights reserved.

Automated summary

Amorphous (FexNiyCoz)(80)B10Si2Cu1Zr7 alloys prepared by melt spinning exhibit good magnetic properties and thermal stability, with alloys containing less than 64% Ni showing a nanocrystalline structure after annealing. The optimal composition for maximum saturation magnetization is found to be (Co + Ni):Fe = 3:7 at a specific Ni content range.