Elastic constants and critical thicknesses of ScGaN and ScAlN
Elastic constants and critical thicknesses of ScGaN and ScAlN
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DOI：
10.1063/1.4848036
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发表时间：
2013-12-28
影响因子：
3.2
通讯作者：
Moram, M. A.
中科院分区：
文献类型：
--
作者：
Zhang, S.;Fu, W. Y.;Moram, M. A.
采用应力-应变法计算了六方晶系ScxGa 1-xN和ScxAl 1-xN在x=0.375时的弹性常数。C-11、C-33、C-44和C-66随着x的增加而降低，而C-12和C-13则略有增加。双轴[0001]泊松比从GaN的0.21增加到Sc0.375Ga0.625N的0.38，从AlN的0.22增加到Sc0.375Al0.625N的0.40，这是由于更大的u值、面内键长和键离子性。随后，使用能量平衡模型计算ScxAl 1-xN/AlN、ScxGa 1-xN/GaN和ScxAl 1-xN/GaN异质结构的应力松弛临界厚度。这些范围从Sc0.375Al0.625N/AlN和Sc0.375Ga0.625N/GaN的2nm到晶格匹配的Sc0.18Al0.82N/GaN的无穷大。(C)2013 AIP Publishing LLC.
Elastic constants of hexagonal ScxGa1-xN and ScxAl1-xN up to x=0.375 were calculated using a stress-strain approach. C-11, C-33, C-44, and C-66 decreased while C-12 and C-13 increased slightly with increasing x. The biaxial [0001] Poisson ratios increased from 0.21 for GaN to 0.38 for Sc0.375Ga0.625N and from 0.22 for AlN to 0.40 for Sc0.375Al0.625N, due to greater u values, in-plane bond lengths and bond ionicities. Subsequently, critical thicknesses for stress relaxation were calculated for ScxAl1-xN/AlN, ScxGa1-xN/GaN, and ScxAl1-xN/GaN heterostructures using an energy balance model. These range from 2 nm for Sc0.375Al0.625N/AlN and Sc0.375Ga0.625N/GaN to infinity for lattice-matched Sc0.18Al0.82N/GaN. (C) 2013 AIP Publishing LLC.