Self-Assembled and STM Tip-induced Structures of organic molecules with carboxylic acid functional group on Cu(110) and Ge(100) surfacesCu(110)와 Ge(100)표면에서 카복실기 그룹을 가진 유기 분자의 자기 조립 구조체 및 STM 탐침에 의해 형성된 구조체 연구
Construction of RAIRS
Reflection absorption infrared spectroscopy (RAIRS) is a very powerful tool for probing vibrations of adsorbed molecules on clean single crystal surface. Since the energy of certain vibrational mode depends on the functional group of molecule, RAIRS is an ideal technique for determining both the nature of the adsorbate species and also its adsorption site and orientation at surfaces. We assemble all apparatuses de-signed and manufactured for incorporating the FT-IR capability into UHV system, and the spectrometer is coupled to a liquid nitrogen cooled narrow band MCT detector which gives an accessible spectral range of 800 - 4000 cm-1. We could obtain highly surface-sensitive RAIRS spectra of organic molecules on Cu(110) surface under UHV conditions.
Self-Assembled and Field-Induced Structures of Glutaric acid on Cu(110)
We have investigated the adsorption structures of glutaric acid (HOOC-(CH2)3-COOH) on the Cu(110) surface as a function of coverage by using scanning tunneling microscopy (STM) and reflection-absorption IR spectroscopy (RAIRS). Above a critical coverage, the molecules self-assemble on Cu(110) into three kinds of well-organized structures at room temperature. In contrast, glutaric acid molecules diffuse freely on Cu(110) at low coverages, and so cannot form ordered structures. Interestingly, we were able with STM to fabricate novel ordered structures of glutaric acid that cannot naturally occur at room temperature. We con-clude that this new structure is created through field-induced assembly.
Self-Assembled Structures of Glutamic acid on Cu(110)
In the present study, we have investigated the self-assembled structures of glutamic acid on Cu(110) as a function of coverage. At low coverage, we can identify row structure in STM image and it is composed of two-lobe feature representing a single molecule. Based on the RAIRS spectra, we could conclude that glutamic acid molecule is anchored to the surface via three functionaliti...