Structural and magnetic properties of GdCo5−xNix
| Autor: | Martin R. Lees, Rachel S. Edwards, Santosh Kumar, Geetha Balakrishnan, Amy L. Tedstone, Julie B. Staunton, Christopher E. Patrick |
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| Rok vydání: | 2019 |
| Předmět: |
Diffraction
Materials science Physics and Astronomy (miscellaneous) chemistry.chemical_element 02 engineering and technology Coercivity 021001 nanoscience & nanotechnology Magnetocrystalline anisotropy 01 natural sciences Condensed Matter::Materials Science Magnetization Crystallography Nickel chemistry Ferrimagnetism 0103 physical sciences Content (measure theory) General Materials Science Crystallite 010306 general physics 0210 nano-technology |
| Zdroj: | Physical Review Materials. 3 |
| ISSN: | 2475-9953 |
| Popis: | ${\mathrm{GdCo}}_{5}$ 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 ${\mathrm{GdCo}}_{5}$ 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 ${\mathrm{GdCo}}_{5\ensuremath{-}x}{\mathrm{Ni}}_{x}$ for $0\ensuremath{\le}x\ensuremath{\le}5$ 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 ${\mathrm{Gd}}_{2}{(\mathrm{Co},\mathrm{Ni})}_{7}$ lamellae for $x\ensuremath{\le}2.5$. Compensation---i.e., the cancellation of the opposing Gd and transition-metal moments---is observed for $1lxl3$ 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 $x\ensuremath{\approx}1$ 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. |
| Databáze: | OpenAIRE |
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