First-principles calculations of the magnetocrystalline anisotropy of the prototype 2:17 cell boundary phase Y(Co$_{1-x-y}$Fe$_x$Cu$_y$)$_5$

Christopher E. Patrick; Munehisa Matsumoto; Julie B. Staunton

doi:10.1016/j.jmmm.2019.01.061

paper

First-principles calculations of the magnetocrystalline anisotropy of the prototype 2:17 cell boundary phase Y(Co $_{1 - x - y}$ Fe $_{x}$ Cu $_{y}$ ) $_{5}$

arXiv:1901.04185 · doi:10.1016/j.jmmm.2019.01.061

Abstract

We present a computational study of the compound Y(Co $_{1 - x - y}$ Fe $_{x}$ Cu $_{y}$ ) $_{5}$ for 0 $\leq x, y \leq 0.2$ . This compound was chosen as a prototype for investigating the cell boundary phase believed to play a key role in establishing the high coercivity of commercial Sm-Co 2:17 magnets. Using density-functional theory, we have calculated the magnetization and magnetocrystalline anisotropy at zero temperature for a range of compositions, modeling the doped compounds within the coherent potential approximation. We have also performed finite temperature calculations for YCo $_{5}$ , Y(Co $_{0.838}$ Cu $_{0.162}$ ) $_{5}$ and Y(Co $_{0.838}$ Fe $_{0.081}$ Cu $_{0.081}$ ) $_{5}$ within the disordered local moment picture. Our calculations find that substituting Co with small amounts of either Fe or Cu boosts the magnetocrystalline anisotropy $K$ , but the change in $K$ depends strongly on the location of the dopants. Furthermore, the calculations do not show a particularly large difference between the magnetic properties of Cu-rich Y(Co $_{0.838}$ Cu $_{0.162}$ ) $_{5}$ and equal Fe-Cu Y(Co $_{0.838}$ Fe $_{0.081}$ Cu $_{0.081}$ ) $_{5}$ , despite these two compositions showing different coercivity behavior when found in the cell boundary phase of 2:17 magnets. Our study lays the groundwork for studying the rare earth contribution to the anisotropy of Sm(Co $_{1 - x - y}$ Fe $_{x}$ Cu $_{y}$ ) $_{5}$ , and also shows how a small amount of transition metal substitution can boost the anisotropy field of YCo $_{5}$ .

arXiv comment23 pages, 7 figures

First-principles calculations of the magnetocrystalline anisotropy of the prototype 2:17 cell boundary phase Y(Co $_{1 - x - y}$ Fe $_{x}$ Cu $_{y}$ ) $_{5}$

Abstract

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First-principles calculations of the magnetocrystalline anisotropy of the prototype 2:17 cell boundary phase Y(Co1−x−y​Fex​Cuy​)5​

Abstract

References in corpus (10)

Cited by in corpus (4)

First-principles calculations of the magnetocrystalline anisotropy of the prototype 2:17 cell boundary phase Y(Co $_{1 - x - y}$ Fe $_{x}$ Cu $_{y}$ ) $_{5}$