Control of magnetism by electrical charge doping or redox reactions in a surface-oxidized Co thin film with a solid-state capacitor structure
Control of magnetism by electrical charge doping or redox reactions in a surface-oxidized Co thin film with a solid-state capacitor structure
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DOI：
10.1063/1.5020932
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发表时间：
2018-03-19
影响因子：
4
通讯作者：
Chiba, D.
中科院分区：
文献类型：
--
作者：
Hirai, T.;Koyama, T.;Chiba, D.
研究了表面自然氧化的Co薄膜中电场对磁性的影响。通过使用原子层沉积（ALD）形成的由HfO 2制成的栅极绝缘体层将EF施加到氧化的Co表面。在适当的温度下沉积的HfO 2层的ALD工艺的样品中的磁各向异性的EF效果的效率是相对较大的相比，先前报道的值与未氧化的Co膜。的双折射率迅速和可逆地跟随在栅极电压的变化。通道电阻的调制最多类似于0.02%。与此相反，一个戏剧性的变化，包括在饱和磁矩和更大的EF-诱导的沟道电阻的调制（类似于10%）的变化大的磁性能，观察在样品中的HfO 2层沉积在远低于适当的温度范围的温度。这些性质的响应是非常缓慢的门电压，这表明氧化还原反应占主导地位的EF在这个样品中的磁性的影响。的电容特性的频率响应进行了检查，以讨论在这里观察到的EF效应的机制的差异。由AIP出版社出版。
We have investigated the electric field (EF) effect on magnetism in a Co thin film with a naturally oxidized surface. The EF was applied to the oxidized Co surface through a gate insulator layer made of HfO2, which was formed using atomic layer deposition (ALD). The efficiency of the EF effect on the magnetic anisotropy in the sample with the HfO2 layer deposited at the appropriate temperature for the ALD process was relatively large compared to the previously reported values with an unoxidized Co film. The coercivity promptly and reversibly followed the variation in gate voltage. The modulation of the channel resistance was at most similar to 0.02%. In contrast, a dramatic change in the magnetic properties including the large change in the saturation magnetic moment and a much larger EF-induced modulation of the channel resistance (similar to 10%) were observed in the sample with a HfO2 layer deposited at a temperature far below the appropriate temperature range. The response of these properties to the gate voltage was very slow, suggesting that a redox reaction dominated the EF effect on the magnetism in this sample. The frequency response for the capacitive properties was examined to discuss the difference in the mechanism of the EF effect observed here. Published by AIP Publishing.