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

Document Type

Article

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.