Structural and magnetic properties of GdCo5 -xNix
Abstract
GdCo5 may be considered as two sublattices—one of Gd and one of Co—whose magnetizations are in antiparallel alignment, forming a ferrimagnet. Substitution of nickel in the cobalt sublattice of GdCo5 has been investigated to gain insight into how the magnetic properties of this prototype rare-earth/transition-metal magnet are affected by changes in the transition-metal sublattice. Polycrystalline samples of GdCo5 -xNix for 0 ≤x ≤5 were synthesized by arc melting. Structural characterization was carried out by powder x-ray diffraction and optical and scanning electron microscope imagings of metallographic slides, the latter revealing a low concentration of Gd2(Co,Ni ) 7 lamellae for x ≤2.5 . Compensation—i.e., the cancellation of the opposing Gd and transition-metal moments—is observed for 1 <x <3 at a temperature which increases with Ni content; for larger x , no compensation is observed below 360 K. A peak in the coercivity is seen at x ≈1 at 10 K coinciding with a minimum in the saturation magnetization. Density-functional theory calculations within the disordered local moment picture reproduce the dependence of the magnetization on Ni content and temperature. The calculations also show a peak in the magnetocrystalline anisotropy at similar Ni concentrations to the experimentally observed coercivity maximum.
- Publication:
-
Physical Review Materials
- Pub Date:
- March 2019
- DOI:
- 10.1103/PhysRevMaterials.3.034409
- arXiv:
- arXiv:1903.11442
- Bibcode:
- 2019PhRvM...3c4409T
- Keywords:
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- Condensed Matter - Materials Science;
- Condensed Matter - Strongly Correlated Electrons
- E-Print:
- 12 pages, 12 figures, 2 tables