Effect of Vanadium Addition on Structure and Soft Magnetic Properties of Nanocrystalline FeCoZrBCu Melt Spun Alloys

In this study, glass forming ability, structure and soft magnetic properties of melt spun ribbons of (Fe1-xCox) 88-yVyZr7B4Cu1alloys with compositions x0.1y2, x0.1y4 and x0.1y6& x0.35y2,x0.35y4 andx0.35y6 have been investigated. All alloys were found to be fully amorphous after melt spinning. Annealing of amorphous ribbons of x0.1 series alloys leads to the formation of bcc alpha-Fe(Co) phase and Fe2Zr phase in the amorphous matrix, while annealing of amorphous ribbons of x0.35 series alloys, leads to the formation of only bcc alpha-Fe(Co) phase in the amorphous matrix. High precision lattice parameter calculations revealed that V addition influences the phase formation in low Co containing x0.1 alloys. It leads to low volume fraction of bcc alpha-Fe(Co) phase and promotes Fe2Zr phase. A higher Co content increases the Curie temperature (Tc) of amorphous phase, while V addition decreases the TC of amorphous phase in both x0.1 and x0.35 series of alloys. Saturation magnetization (Ms) ofx0.35 alloys are higher than of x0.1 alloy due to higher Co content and the Ms decreases with increasing V content due to its non-magnetic nature. Coercivity was found to be increased with annealing in x0.35 alloys due to the low volume fraction formation of bcc alpha-Fe(Co) phase and Fe2Zr phase. The coercivity decreases with increasing V addition in x0.35 alloys as spun ribbons and a lowest coercivity of 0.13 Oe has been obtained in x0.35y6 alloy which is one of the lowest among FeCoZrBCu alloys reported.