Applied voltage dependence of nano-oxidation of ferromagnetic thin films using atomic force microscope
Applied voltage dependence of nano-oxidation of ferromagnetic thin films using atomic force microscope
复制标题
使用原子力显微镜研究铁磁薄膜纳米氧化的施加电压依赖性
DOI：
10.1063/1.1540046
复制
发表时间：
2003
影响因子：
3.2
通讯作者：
J. Shirakashi
中科院分区：
文献类型：
--
作者：
Y. Takemura;Seiichi Kidaka;Keizo Watanabe;Yasuaki Nasu;Tsutomu Yamada;J. Shirakashi
利用原子力显微镜，采用纳米氧化技术制备了镍、钴、铬氧化物纳米点。通过改变施加在悬臂梁上的脉冲电压从2到10 V，可以将点的尺寸控制在40到200 nm之间。为了定量评价纳米结构的尺寸，计算了悬臂梁发出的电场。阈电场强度定义为促进氧化的最小强度。通过对实验结果的拟合，得到了107 V/m量级的阈值场强。计算结果很好地拟合了氧化铬点尺寸与电压的关系。铁磁基氧化物的网点大小是波动的，与计算结果不一致。理论分析表明，纳米结构的尺寸与悬臂梁与薄膜表面的距离无关，而与悬臂梁的曲率半径密切相关。
Nanodots of Ni, CoFe, and Cr oxide were fabricated by the nano-oxidation technique using atomic force microscope. The dot size was controlled from 40 to 200 nm by changing the pulse voltage applied to the cantilever from 2 to 10 V. In order to evaluate the size of the nanostructures quantitatively, the electric field emitted from the cantilever was calculated. The threshold electric field strength was defined as the minimum strength to promote the oxidation. The threshold field strength of the order of 107 V/m was derived by fitting the experimental results. The voltage dependence of the size of fabricated Cr-oxide dots was fitted well by the calculation. The dot size of the ferromagnet-based oxide was fluctuating and did not agree with the calculation. From the theoretical analysis, it was suggested that the size of the nanostructures did not depend on the distance between the cantilever and film surface, but significantly depended on the curvature radius of the cantilever.