Self-Assembled Organic Radicals on Au(111) Surfaces: A Combined ToF-SIMS, STM, and ESR Study

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• 作者：Matteo Mannini ; Lorenzo Sorace ; Lapo Gorini ; Federica M. Piras ; Andrea Caneschi ; Agnese Magnani ; Stefano Menichetti ; Dante Gatteschi
• 刊名：Langmuir
• 出版年：2007
• 出版时间：February 27, 2007
• 年：2007
• 卷：23
• 期：5
• 页码：2389 - 2397
• 全文大小：655K
• 年卷期：v.23,no.5(February 27, 2007)
• ISSN：1520-5827

文摘

Electron spin resonance (ESR), time-of-flight secondary ion mass spectrometry (ToF-SIMS), and scanning tunnelingmicroscopy (STM) have been used in parallel to characterize the deposition on gold surface of a series of nitronylnitroxide radicals. These compounds have been specifically synthesized with methyl-thio linking groups suitable tointeract with the gold surface to form self-assembled monolayers (SAMs), which can be considered relevant in theresearch for molecular-based spintronics devices, as suggested in recent papers. The degree of the expected orderingon the surface of these SAMs has been tuned by varying the chemical structure of synthesized radicals. ToF-SIMShas been used to support the evidence of the occurrence of the deposition process. STM has shown the differentqualities of the obtained SAMs, with the degree of local order increasing as the degree of freedom of the moleculeson the surface is decreased. Finally, ESR has confirmed that the deposition process does not affect the paramagneticcharacteristics of radicals and that it affords a complete single-layered coverage of the surface. Further, the absenceof angular dependence in the spectra indicates that the small regions of local ordering do not give rise to a long-rangeorder and suggests a quite large mobility of the radical on the surface, probably due to the weak interaction with goldprovided by the methyl-thio linking group.