Development and intrinsic properties of hexagonal ferromagnetic (Zr,Ti)Fe₂

Authors

Wenyong Zhang, University of Nebraska-LincolnFollow
Xingzhong Li, University of Nebraska-LincolnFollow
Shah R. Valloppilly, University of Nebraska-LincolnFollow
Ralph A. Skomski, University of Nebraska-LincolnFollow
Jeffrey E. Shield, University of Nebraska-LincolnFollow
David J. Sellmyer, University of Nebraska-LincolnFollow

Document Type

Article

Date of this Version

2014

Citation

JOURNAL OF APPLIED PHYSICS 115 (2014)

Abstract

Nanocrystalline Ti_0.75Zr_0.25Fe_2+x (x=0-0.4) and Ti_0.75-yB_yZr_0.25Fe_2.4 (y=0-0.35) with high saturation magnetization have been fabricated by the melt-spinning technique. Nanocrystalline Ti_0.75Zr_0.25Fe_2+x consists of the hexagonal C14 Laves phase (Ti,Zr)Fe₂. Fe addition decreases the lattice parameter a and shrinks the cell volume. The antiferromagnetic Fe-Fe interactions may decrease with the increase of x, leading to a significant enhancement of saturation polarization (Js) and Curie temperature (Tc). The magnetocrystalline anisotropy constant K also increases with increasing x. Excessive Fe addition (x>0.25) may induce structural disorder which lowers the Js and Tc. Nanocrystalline Ti_0.75-yB_yZr_0.25Fe_2.4 is composed of hexagonal (Ti,Zr)Fe₂ and Fe-rich amorphous phases with relatively high Js. The lattice parameters a, c and cell volume V are almost unchanged with the increase of y for y≥0.16. Simultaneously, the Tc of (Ti,Zr)Fe₂ remains unchanged, indicating that B does not enter this lattice but takes part in forming the amorphous phase, in good agreement with the X-ray diffraction results. The volume fraction of the amorphous phase increases with the increase of B content and results in a large enhancement of Js up to 10.8 kG. Further B addition (y>0.30) decreases Js, possibly due to the decrease of the Js of the amorphous phase.