The effect of P on the glass forming ability and soft magnetic properties of Co–Fe–P–Si–B–C–Mo bulk glassy alloys

• The thermal stability of supercooled liquid increased with increasing the P contents.
• Co-based bulk glassy alloys with diameters up to 5 mm and saturation magnetization of 1.08 T were synthesized by copper mold casting.
• The Co45.6Fe30.4PxSi11.4−xB6.6C4Mo2 glassy alloys exhibit good soft magnetic properties.

Co-based bulk ferromagnetic glassy alloys with diameters up to 5 mm were formed in Co45.6Fe30.4PxSi11.4−xB6.6C4Mo2 system by the copper mold casting method. The effect of P addition on the glass-forming ability (GFA) and soft magnetic properties in the alloys system was investigated. In addition to the increase of glass-forming ability, increasing P content was found to be effective for the improvement of soft-magnetic properties. The bulk glassy alloys exhibit excellent soft-magnetic properties, i.e., high saturation magnetization of 1.08 T, low coercive force within 2.0–3.4 A/m, high permeability of 15795 at 1 KHz, and Curie temperature of 665–694 K. The successful synthesis of the Co45.6Fe30.4PxSi11.4−xB6.6C4Mo2 bulk glassy alloys system exhibiting high GFA and good soft-magnetic properties is encouraging for the future applications of structural and functional materials.