Magnetism and structure of chemically disordered Fe Pt 3 nanocubes
Magnetism and structure of chemically disordered Fe Pt 3 nanocubes
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DOI：
10.1103/physrevb.75.134410
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发表时间：
2007-04
影响因子：
3.7
通讯作者：
O. Margeat;M. Tran;M. Spasova;M. Farle
中科院分区：
文献类型：
--
作者：
O. Margeat;M. Tran;M. Spasova;M. Farle
我们报道了边长为$8\phantom{\rule{0.3em}{0ex}}\mathrm{nm}$且尺寸分布窄的单晶$\mathrm{Fe}{\mathrm{Pt}}_{3}$纳米立方体的化学合成、晶体结构和磁性能。制备的立方体具有{100}个晶面，处于fcc化学无序相。纳米立方的自组装导致⟨100⟩方向垂直于基板平面的方形超晶格。每个$\mathrm{Fe}{\mathrm{Pt}}_{3}$公式单位的平均磁矩$0.63{\ensuremath{\mu}}_{B}$和粒子的居里温度$({T}_{C}=255\phantom{\rule{0.3em}{0ex}}\mathrm{K})$降低了20% and approximately 30% with respect to those of the bulk alloy. The effective magnetic anisotropy energy density ${K}_{\mathit{eff}}=(6.7\ifmmode\pm\else\textpm\fi{}1)\ifmmode\times\else\texttimes\fi{}{10}^{4}\phantom{\rule{0.3em}{0ex}}\mathrm{J}∕{\mathrm{m}}^{3}$ at $5\phantom{\rule{0.3em}{0ex}}\mathrm{K}$ is found to be larger by at least a factor of 2 with respect to bulk values. The temperature dependence of ${K}_{\mathit{eff}}$, which is of single-ion origin, follows the magnetization $M$ according to ${K}_{\mathit{eff}}\ensuremath{\sim}M{(T)}^{2.1}$.
We report the chemical synthesis, crystal structure, and magnetic properties of single-crystalline $\mathrm{Fe}{\mathrm{Pt}}_{3}$ nanocubes with a side length of $8\phantom{\rule{0.3em}{0ex}}\mathrm{nm}$ and a narrow size distribution. As-prepared cubes are in the fcc chemically disordered phase with {100} crystal facets. Self-assembly of the nanocubes results in square superlattices with the ⟨100⟩ directions oriented perpendicular to the substrate plane. The average magnetic moment of $0.63{\ensuremath{\mu}}_{B}$ per $\mathrm{Fe}{\mathrm{Pt}}_{3}$ formula unit and the Curie temperature $({T}_{C}=255\phantom{\rule{0.3em}{0ex}}\mathrm{K})$ of the particles are found to be reduced by 20% and approximately 30% with respect to those of the bulk alloy. The effective magnetic anisotropy energy density ${K}_{\mathit{eff}}=(6.7\ifmmode\pm\else\textpm\fi{}1)\ifmmode\times\else\texttimes\fi{}{10}^{4}\phantom{\rule{0.3em}{0ex}}\mathrm{J}∕{\mathrm{m}}^{3}$ at $5\phantom{\rule{0.3em}{0ex}}\mathrm{K}$ is found to be larger by at least a factor of 2 with respect to bulk values. The temperature dependence of ${K}_{\mathit{eff}}$, which is of single-ion origin, follows the magnetization $M$ according to ${K}_{\mathit{eff}}\ensuremath{\sim}M{(T)}^{2.1}$.