Cubic versus spherical magnetic nanoparticles: The role of surface anisotropy
Cubic versus spherical magnetic nanoparticles: The role of surface anisotropy
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DOI：
10.1021/ja0768744
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发表时间：
2008-10-08
影响因子：
15
通讯作者：
Nogues, J.
中科院分区：
文献类型：
--
作者：
Salazar-Alvarez, G.;Qin, J.;Nogues, J.
相似尺寸的磁赤铁矿（γ-Fe2O3）立方体和球形纳米颗粒的磁性已通过实验和理论研究。纳米粒子的阻断温度 TB 取决于其形状，球形纳米粒子的 TB 更大。其他低温特性，如饱和磁化强度、矫顽力、环位移或自旋倾斜都非常相似。实验有效各向异性和蒙特卡罗模拟表明，两种形态的不同随机表面各向异性与γ-Fe2O3的低磁晶各向异性相结合是这些效应的根源。
The magnetic properties of maghemite (gamma-Fe2O3) cubic and spherical nanoparticles of similar sizes have been experimentally and theoretically studied. The blocking temperature, TB, of the nanoparticles depends on their shape, with the spherical ones exhibiting larger TB. Other low temperature properties such as saturation magnetization, coercivity, loop shift or spin canting are rather similar. The experimental effective anisotropy and the Monte Carlo simulations indicate that the different random surface anisotropy of the two morphologies combined with the low magnetocrystalline anisotropy of gamma-Fe2O3 is the origin of these effects.