Magnetic films epitaxially grown on semiconductors
Magnetic films epitaxially grown on semiconductors
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DOI：
10.1016/s0304-8853(97)00209-6
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发表时间：
1997-11
影响因子：
2.7
通讯作者：
M. Zölfl;M. Brockmann;M. Köhler;S. Kreuzer;T. Schweinböck;S. Miethaner;F. Bensch;G. Bayreuther
中科院分区：
文献类型：
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作者：
M. Zölfl;M. Brockmann;M. Köhler;S. Kreuzer;T. Schweinböck;S. Miethaner;F. Bensch;G. Bayreuther
未来的“磁电子学”除了利用电子的电荷外，还利用电子的自旋，需要将自旋极化电子从铁磁金属注入到半导体中。为此，本研究试图避免形成非磁性界面相或“磁死层”，这种现象过去在 GaAs(0 0 1) 上外延生长的 Fe 薄膜中发现过。 Fe(0 0 1) 薄膜通过分子束外延和磁控溅射在室温下的贫砷 GaAs(0 0 1) 表面上生长。两种沉积方法都实现了非常好的外延生长。与之前的报道相比，MBE 生长的超薄膜在 Fe/GaAs 界面处表现出增强的基态净磁化强度和完整的体磁矩。这可能是迈向使用自旋极化电子传输的半导体器件的重要一步。薄膜的面内磁各向异性通常由四重项和单轴项组成。在 7 单层厚度时，仅观察到强烈的单轴贡献，这被认为是由 GaAs(0 0 1) 表面的悬挂键的本征各向异性引起的。这对于未来的内存或交换应用也可能是有用的属性。
Future ‘magneto-electronics’ exploiting the spin of the electron in addition to its charge will require the injection of spin-polarized electrons from a ferromagnetic metal into a semiconductor. To this purpose an attempt has been made in the present study to avoid the formation of a non-magnetic interface phase or ‘magnetically dead layers’ which have been found in the past in Fe films epitaxially grown on GaAs(0 0 1). Fe(0 0 1) films were grown by molecular beam epitaxy and magnetron sputtering on As depleted GaAs(0 0 1) surfaces held at room temperature. Very good epitaxial growth is achieved by both deposition methods. MBE grown ultrathin films show an enhanced ground state net magnetization and the full bulk magnetic moments at the Fe/GaAs interface in contrast to previous reports. This might be an important step towards semiconductor devices using spin polarized electron transport. The in-plane magnetic anisotropy of the films generally consists of a fourfold and a uniaxial term. At 7 monolayer thickness only a strong uniaxial contribution is observed which is supposed to result from the intrinsic anisotropy of the dangling bonds at the GaAs(0 0 1) surface. This could also be a useful property for future memory or switching applications.