Phase transformation and magnetic properties of rapidly solidified Mn-Al-C alloys modified with Zr

Authors

Yunlong Geng, University of Nebraska–LincolnFollow
Micheal J. Lucis, University of Nebraska–Lincoln
Pamela Rasmussen, Raymond Central High School
Jeffrey E. Shield, University of Nebraska–LincolnFollow

Date of this Version

2015

Citation

JOURNAL OF APPLIED PHYSICS 118, 033905 (2015)

Abstract

Mn_54-xAl₄₃C₃Zr_x (x=1, 3) alloys were prepared by rapid solidification followed by heat treatment to produce the ferromagnetic s phase. The substitution of Zr for Mn in the structure resulted in an increase of the saturation magnetization (Ms) compared to that of Mn_54-xAl₄₃C₃. While the highest Ms (12861 emu/g) was obtained in Mn_54-xAl₄₃C₃Zr₁, the coercivity was also improved to 1.62 kOe, compared to 1.25 kOe for Mn_54-xAl₄₃C₃. To further improve the coercivity through grain refinement, additional C (1%, 3%, 5%, and 7%) was added to Mn_54-xAl₄₃C₃Zr₁. An increase in the coercivity was observed due to a decrease of grain size and the formation of nonmagnetic phases, which reduced the magnetostatic interactions between the s-phase grains. However, excess C reduced the saturation magnetization due to the formation of the other non-ferromagnetic phases, including e, c2, and b phases.