Abstract
This study investigates the structural and magnetic properties of ultra-high coercivity (Fe(80)B(14)Nb(6))(0.88)Dy(0.12) alloys, doped with 0.5-5 at.% of selected metallic additions: magnetic (Ni, Co) and non-magnetic (Pt, Cu) elements. Material characterization involved both structural and magnetic measurements. Alloys containing dopant concentrations up to 2 at.% exhibited similar phase compositions, with the Dy(2)Fe(14)B compound being dominant. Magnetic hysteresis loops revealed a superposition of two components: magnetically soft and hard phases. A significant change in magnetic properties was observed within the 0.5 to 1 at.% dopant concentration range. Notably, the addition of 0.5 at.% Ni increased the apparent anisotropy field from 5.2 T to 7.5 T. Furthermore, 0.5 at.% Pt led to an increase in the coercive field from 4.6 T to 5.5 T. These additions influenced crystallization, resulting in the formation of a more regular microstructure without submicrometric dendrite branches, when compared to the base alloy.