Structure of CdS-Cd-Arachidate/Arachidic Acid Composite Multilayers
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- 作者：Satish Vitta ; T. H. Metzger ; S. S. Major ; A. Dhanabalan ; and S. S. Talwar
- 刊名：Langmuir
- 出版年：1998
- 出版时间：March 31, 1998
- 年：1998
- 卷：14
- 期：7
- 页码：1799 - 1803
- 全文大小：134K
- 年卷期：v.14,no.7(March 31, 1998)
- ISSN：1520-5827
文摘
A composite multilayer consisting of semiconducting CdSdistributed in Cd-arachidate/arachidic acidlayers was prepared by exposing the precursor Cd-arachidatemultilayers to H2S. The structures of theprecursor multilayers and the modified multilayers were studied bygrazing incidence reflection/diffractionusing X-rays from a conventional generator and a synchrotron source.The formation of CdS in arachidicacid/Cd-arachidate composite multilayers resulted in the introductionof a new layered structure witha period of 4.37 nm compared to the precursor multilayer period of 5.55nm. The reduction in the periodof the multilayers is consistent with the observation of a tiltedstructure found in alkanethiol and H2Sexposed Cd-stearate multilayers. The lateral morphology of CdSwhich is replicated between the successivelayers in the vertical direction is different when compared to the headgroup morphology in the precursormultilayer. The molecular arrangement in the plane of theCd-arachidate precursor multilayer is foundto be orthorhombic while the CdS molecules in the modified multilayerare arranged in a hexagonal array.The lateral size of the CdS domains/particles is found to be ~13nm, at least an order of magnitude greaterthan the layer thickness. This clearly indicates that the CdSparticles are quasi-2D in nature and are diskshaped.