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Effect of annealing on the magnetic properties and microstructure of amorphous Co75Si10B15

Journal Article


Abstract


  • The influence of annealing on low and high frequency magnetic behaviour in amorphous ribbons of nominal composition, Co75Si10B15 was investigated at temperatures both above and below that required for the crystallisation of ε-Co from the amorphous matrix. Low-frequency (0-400 Hz) soft magnetic properties improved on annealing below the crystallisation temperature while high frequency (1-50 kHz) properties were optimised in ribbons annealed at temperatures resulting in approximately 1% crystallisation. Crystallisation resulted in asymmetrically displaced hysteresis loops, the loop displacement increasing with increasing number of discrete ε-Co crystals or crystal clusters. Based on magnetic measurements, differential scanning calorimetry and microstructural observations, it was concluded that the shift in the hysteresis loops originates from the presence of ε-Co crystals within the bulk, rather than at the ribbon surfaces. This type of shift is manifest as a displacement of the coercivities towards the direction of the initial magnetisation and occurs in a range of amorphous alloys which crystallise the ε-Co phase in the bulk. Shifts associated with surface magnetic phases in both Fe-and Co-based alloys may be characterised by a dip in the second quadrant of the B-H loop and/or a skewing of the loop towards lower inductions for a given magnetisation.

Publication Date


  • 1996

Citation


  • Shaikh, A. K., Wexler, D., & Delamore, G. W. (1996). Effect of annealing on the magnetic properties and microstructure of amorphous Co75Si10B15. Journal of Magnetism and Magnetic Materials, 152(3), 345-352. doi:10.1016/0304-8853(95)00480-7

Scopus Eid


  • 2-s2.0-0030562034

Start Page


  • 345

End Page


  • 352

Volume


  • 152

Issue


  • 3

Abstract


  • The influence of annealing on low and high frequency magnetic behaviour in amorphous ribbons of nominal composition, Co75Si10B15 was investigated at temperatures both above and below that required for the crystallisation of ε-Co from the amorphous matrix. Low-frequency (0-400 Hz) soft magnetic properties improved on annealing below the crystallisation temperature while high frequency (1-50 kHz) properties were optimised in ribbons annealed at temperatures resulting in approximately 1% crystallisation. Crystallisation resulted in asymmetrically displaced hysteresis loops, the loop displacement increasing with increasing number of discrete ε-Co crystals or crystal clusters. Based on magnetic measurements, differential scanning calorimetry and microstructural observations, it was concluded that the shift in the hysteresis loops originates from the presence of ε-Co crystals within the bulk, rather than at the ribbon surfaces. This type of shift is manifest as a displacement of the coercivities towards the direction of the initial magnetisation and occurs in a range of amorphous alloys which crystallise the ε-Co phase in the bulk. Shifts associated with surface magnetic phases in both Fe-and Co-based alloys may be characterised by a dip in the second quadrant of the B-H loop and/or a skewing of the loop towards lower inductions for a given magnetisation.

Publication Date


  • 1996

Citation


  • Shaikh, A. K., Wexler, D., & Delamore, G. W. (1996). Effect of annealing on the magnetic properties and microstructure of amorphous Co75Si10B15. Journal of Magnetism and Magnetic Materials, 152(3), 345-352. doi:10.1016/0304-8853(95)00480-7

Scopus Eid


  • 2-s2.0-0030562034

Start Page


  • 345

End Page


  • 352

Volume


  • 152

Issue


  • 3