Materials and Nanoscience, Nebraska Center for (NCMN)


Date of this Version



Published by Am Inst of Physics. J. Appl. Phys. 99, 08B514 2006. Copyright 2006. Permission to use.


Rapid solidification has been utilized to produce a series of Pr–Co alloys between the Pr2Co17 and PrCo5 stoichiometries. In this system, PrCo5 has easy axis magnetization while Pr2Co17 has easy-plane magnetization. Alloys of the form (PrxCo1-x)94Ti3C3 with x ranging from 0.105 corresponding to the Pr2Co17 compound tox=0.167 corresponding to the PrCo5 compound were produced by melt spinning at a tangential wheel speed of 40 m/ s. The rapid solidification and alloying additions were found to suppress the formation of the Pr2Co17 ordered phase, leading to the formation of the disordered TbCu7-type structure over a range of Pr/Co ratios. Hysteresis loops were characterized by a smooth demagnetization curve reflective of single-phase demagnetization. Heat treatment at 800 °C led to the formation of the Pr2Co17 and PrCo5 phases, and the presence of the soft magnetic Pr2Co17 phase drastically decreased the coercivity. The soft magnetic behavior was consistent with in-plane magnetization of the Pr2Co17 structure that formed during heat treatment. However, the relatively high coercivity observed in the as-solidified alloys with the disordered TbCu7-type structure suggests that dumbbell disorder may create easy axis magnetization, and changes in saturation magnetization also imply that dumbbell configuration is important to the magnetic properties.