Structure and Magnetic Properties of RFe6−xGa6+x (R=rare earth)

Authors

Yongquan Guo, Southern Illinois University Carbondale
Naushad Ali, Southern Illinois University Carbondale
Mauro R. Sardela, Materials Research Laboratory

Comments

© 2002 American Institute of Physics

Published in Journal of Applied Physics, Vol. 91 No. 10 (2002) at doi: 10.1063/1.1447507

Abstract

The crystal structures and magnetic properties of RFe_6−xGa_6+x (R=Ce, Pr, Nd, Sm, and Gd) alloys have been investigated by x-ray powder diffraction and magnetic measurement. A ternary intermetallic compound with an orthorhombic ScFe₆Ga₆ type structure is found in these alloys. The lattice parameter contraction is observed when the higher atomic number lanthanides are substituted into the intermetallic. In each unit cell, there are six nonequivalent crystal positions, i.e., 2a, 4e, 4f, 4g, 4h, and 8k, which are occupied by 2R, 4Ga^I, 4(Fe^I,Ga), 4Ga^II, 4Ga^III, and 8Fe^II, respectively. The RFe_6−xGa_6+x alloys have ferromagnetic ordering but the magnetic transitions have been found in Nd based alloy. The RFe_6−xGa_6+x alloys show a soft magnetic behavior but the magnetization hysteresis loops have been observed in the Nd and Sm alloys at 5 K. The saturated magnetic moments per molecule tend to increase from Ce to Nd. However, a drastic decrease of magnetic moment in GdFe₆Ga₆ alloy is observed and is likely due to the Gd spin alignment being antiparallel to Fe spin. The saturation magnetic moments of these alloys are calculated and agree with the experimental values.

Recommended Citation

Guo, Yongquan, Ali, Naushad and Sardela, Mauro R. "Structure and Magnetic Properties of RFe6−xGa6+x (R=rare earth)." (May 2002).