Anisotropic ferromagnetism in substituted zinc oxide
Anisotropic ferromagnetism in substituted zinc oxide
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DOI：
10.1103/physrevlett.93.177206
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发表时间：
2004-10-22
影响因子：
8.6
通讯作者：
Coey, JMD
中科院分区：
文献类型：
--
作者：
Venkatesan, M;Fitzgerald, CB;Coey, JMD
在由含5原子的靶制成的（110）取向ZnO薄膜中观察到室温铁磁性。%的Sc、Ti、V、Fe、Co或Ni，但不含Cr、Mn或Cu离子。含Co和Ti的氧化物有较大的磁矩，分别为2.6 μ（B）和0.5 μ（B）/掺杂原子。也有一个时刻为0.3 μ（B）/Sc。磁化是非常各向异性的，与变化高达3的因素取决于所施加的领域相对于基板的方向。结果进行解释的自旋分裂施主杂质带模型，它可以占铁磁性绝缘或导电高k氧化物的磁性离子的浓度远远低于逾渗阈值。磁矩与薄膜中的双电子缺陷以及3d离子的未成对电子有关。
Room-temperature ferromagnetism is observed in (110) oriented ZnO films made from targets containing 5 at. % of Sc, Ti, V, Fe, Co, or Ni, but not Cr, Mn, or Cu ions. There are large moments, 2.6mu(B) and 0.5mu(B)/dopant atom for Co- and Ti-containing oxides, respectively. There is also a moment of 0.3mu(B)/Sc. Magnetization is very anisotropic, with variations of up to a factor of 3 depending on the orientation of the applied field relative to the substrate. Results are interpreted in terms of a spin-split donor impurity-band model, which can account for ferromagnetism in insulating or conducting high-k oxides with concentrations of magnetic ions that lie far below the percolation threshold. Magnetic moments are associated with two-electron defects in the films as well as unpaired electrons of the 3d ions.