McAlinden N, McGilp J F
School of Physics, Trinity College Dublin, Dublin 2, Republic of Ireland.
J Phys Condens Matter. 2009 Nov 25;21(47):474208. doi: 10.1088/0953-8984/21/47/474208. Epub 2009 Nov 5.
The distinct optical signatures of aligned single and double Au atom chain structures, grown on vicinal Si(111) substrates, have been identified using reflectance anisotropy spectroscopy (RAS). Deposition of 0.04 monolayers (ML) of amorphous Si (a-Si) at room temperature perturbs the anisotropic optical response of the double chain structure. By one third of a monolayer, no significant optical anisotropy associated with the chains remains. No anisotropic response re-emerges at higher coverages, up to 4.6 nm (14.5 ML) where there is recent evidence that the crystal structure of the double chain phase is maintained under the cap. The RAS results show that the anisotropic properties of the phase are quenched by a-Si adsorption, even though the crystal structure of the capped phase appears to be preserved.
利用反射率各向异性光谱（RAS），已识别出在近邻Si(111)衬底上生长的对齐单金原子链和双金原子链结构的独特光学特征。室温下沉积0.04单层（ML）的非晶硅（a-Si）会扰乱双链结构的各向异性光学响应。当沉积量达到三分之一单层时，与链相关的显著光学各向异性就不再存在。在高达4.6纳米（14.5 ML）的更高覆盖度下，没有各向异性响应重新出现，不过最近有证据表明，在覆盖层之下双链相的晶体结构得以维持。RAS结果表明，尽管覆盖相的晶体结构似乎得以保留，但该相的各向异性特性会被a-Si吸附淬灭。
