High spin-filter efficiency in a Co ferrite fabricated by a thermal oxidation
High spin-filter efficiency in a Co ferrite fabricated by a thermal oxidation
复制标题
DOI：
10.1063/1.3318297
复制
发表时间：
2010-02
影响因子：
4
通讯作者：
Y. Takahashi;S. Kasai;T. Furubayashi;S. Mitani;K. Inomata;K. Hono
中科院分区：
文献类型：
--
作者：
Y. Takahashi;S. Kasai;T. Furubayashi;S. Mitani;K. Inomata;K. Hono
用热氧化法制备的钴铁氧体作为自旋滤波器进行了测试。使用Pt/CoFe 2 O 4/MgO/Co磁性隧道结，在10 K和室温下分别证实了44%和4.3%的自旋过滤效率。随着偏压的增加，在10 K下的隧道磁电阻（TMR）先增加后减小。这被解释为通过在Co铁氧体中的自旋向下导带的隧穿。由于室温下的电子是由于Co铁氧体中缺陷态上的跳跃传导，因此减少缺陷将是实现更高自旋过滤器效应的关键。
Co ferrites fabricated by a thermal oxidation have been tested as a spin filter. Spin-filter efficiencies of 44% and 4.3% were confirmed at 10 K and RT, respectively, using a magnetic tunnel junction of Pt/CoFe2O4/MgO/Co. By increasing the bias voltage, the tunneling magnetoresistance (TMR) at 10 K increases then decreases. This is interpreted as a tunneling via spin-down conduction band in the Co ferrite. Since the electron at RT is attributed to a hopping conduction on the defect states in the Co ferrite, the reduction of the defects will be the key to achieving a higher spin-filter effect.