Atomic rearrangements in amorphous Al2O3 under electron-beam irradiation
Atomic rearrangements in amorphous Al2O3 under electron-beam irradiation
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DOI：
10.1063/1.4790705
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发表时间：
2013-02-14
影响因子：
3.2
通讯作者：
Nakajima, H.
中科院分区：
文献类型：
--
作者：
Nakamura, R.;Ishimaru, M.;Nakajima, H.
利用透射电子显微镜（TEM）研究了25-300 keV宽电子能量范围内非晶Al_2 O_3（a-Al_2 O_3）的辐照诱导晶化过程。γ-Al 2 O 3纳米晶的形成是通过辐照α-Al 2 O 3薄膜沿着与晶粒中的纳米空隙的形成而诱导的，而与加速电压无关。随着电子能量的降低，晶化变得更加明显，表明电子激发过程在γ-Al 2 O3的形成中起主导作用。径向分布分析表明，a-Al_2 O_3通过“激发”（“受激”）非晶态转变为c相，在该非晶态中，不稳定的短程Al-O键的断裂和重排，五配位的Al-O（AlO 5）基本单元。(C)2013年美国物理学会。[http：//dx.doi.org/10.1063/1.4790705]
The electron-irradiation-induced crystallization of amorphous Al2O3 (a-Al2O3) was investigated by in-situ transmission electron microscopy under the wide electron-energy region of 25-300 keV. The formation of gamma-Al2O3 nanocrystallites was induced by irradiating the a-Al2O3 thin film along with the formation of nanovoids in the crystalline grains regardless of the acceleration voltage. The crystallization became more pronounced with decreasing the electron energy, indicating that electronic excitation processes play a dominant role in the formation of gamma-Al2O3. Radial distribution analyses suggested that a-Al2O3 transforms to c-phase via the "excited" ("stimulated") amorphous state, in which the breaking and rearrangement of unstable short-range Al-O bonds, i.e., fivefold-coordinated Al-O (AlO5) basic units, occur. (C) 2013 American Institute of Physics. [http://dx.doi.org/10.1063/1.4790705]