当前位置: X-MOL 学术ACS Appl. Mater. Interfaces › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Phase Selection and Structure of Low-Defect-Density γ-Al2O3 Created by Epitaxial Crystallization of Amorphous Al2O3
ACS Applied Materials & Interfaces ( IF 8.3 ) Pub Date : 2020-12-08 , DOI: 10.1021/acsami.0c17606
Rui Liu 1 , Omar Elleuch 2 , Zhongyi Wan 3 , Peng Zuo 1 , Tesia D. Janicki 3 , Adam D. Alfieri 1 , Susan E. Babcock 1 , Donald E. Savage 1 , J. R. Schmidt 3 , Paul G. Evans 1 , Thomas F. Kuech 2
Affiliation  

A multistep phase sequence following the crystallization of amorphous Al2O3 via solid-phase epitaxy (SPE) points to methods to create low-defect-density thin films of the metastable cubic γ-Al2O3 polymorph. An amorphous Al2O3 thin film on a (0001) α-Al2O3 sapphire substrate initially transforms upon heating to form epitaxial γ-Al2O3, followed by a transformation to monoclinic θ-Al2O3, and eventually to α-Al2O3. Epitaxial γ-Al2O3 layers with low mosaic widths in X-ray rocking curves can be formed via SPE by crystallizing the γ-Al2O3 phase from amorphous Al2O3 and avoiding the microstructural inhomogeneity arising from the spatially inhomogeneous transformation to θ-Al2O3. A complementary molecular dynamics (MD) simulation indicates that the amorphous layer and γ-Al2O3 have similar Al coordination geometry, suggesting that γ-Al2O3 forms in part because it involves the minimum rearrangement of the initially amorphous configuration. The lattice parameters of γ-Al2O3 are consistent with a structure in which the majority of the Al vacancies in the spinel structure occupy sites with tetrahedral coordination, consistent with the MD results. The formation of Al vacancies at tetrahedral spinel sites in epitaxial γ-Al2O3 can minimize the epitaxial elastic deformation of γ-Al2O3 during crystallization.

中文翻译:

相选择,低缺陷密度的结构的γ-Al 2 Ø 3的创Al基非晶态的附生结晶2 Ø 3

的无定形铝结晶以下多步相序2 ö 3通过固相外延(SPE)指向的方法来创建的亚稳立方γ-Al系的低缺陷密度的薄膜2 ö 3多晶型物。非晶质的Al 2 ö 3(0001)的α-Al上的薄膜2 ö 3蓝宝石衬底最初在加热以形成外延的γ-Al变换2 ö 3,随后通过转化到单斜θ-Al系2 ö 3,并最终到的α-Al 2 ö 3。外延的γ-Al 2 ö 3具有低镶嵌宽度层在X射线摇摆曲线可以通过SPE通过结晶的γ-Al来形成2 ö 3由无定形Al相2 ö 3和避免从空间不均匀变换所产生的微结构不均一性θ-Al系2 ö 3。互补的分子动力学(MD)模拟表示该无定形层和在γ-Al 2 ö 3具有类似的Al配位几何形状,这表明在γ-Al 2所ö 3部分地形成,因为它涉及到最初的无定形结构的最小重排。的晶格参数的γ-Al 2 ö 3这与其中尖晶石结构中的大部分Al空位占据具有四面体配位的位点的结构一致,这与MD结果一致。的Al空位在外延四面体尖晶石位点的形成的γ-Al 2 ö 3可以最小化的γ-Al的外延弹性变形2 ö 3结晶期间。
更新日期:2020-12-23
down
wechat
bug