Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

STM studies

Chen S J, Sanz F, Ogietree D F, Flaiimark V M, Devine T M and Saimeron M 1993 Seiective dissoiution of copper from Au-rich Cu-Au aiioys an eiectrochemicai STM study Surf. Sol. 292 289... [Pg.1723]

The above stm study also discovered a facile transport of surface gold atoms in the presence of the Hquid phase, suggesting that the two-step mechanism does not provide a complete picture of the surface reactions, and that adsorption/desorption processes may have an important role in the formation of the final equiHbrium stmcture of the monolayer. Support for the importance of a desorption process comes from atomic absorption studies showing the existence of gold in the alkanethiol solution. The stm studies suggest that this gold comes from terraces, where single-a tomic deep pits are formed (281—283). [Pg.541]

Germanium In situ STM studies on Ge electrodeposition on gold from an ionic liquid have quite recently been started at our institute [59, 60]. In these studies we used dry [BMIM][PF<3] as a solvent and dissolved Gel4 at estimated concentrations of 0.1-1 mmol 1 the substrate being Au(lll). This ionic liquid has, in its dry state, an electrochemical window of a little more than 4 V on gold, and the bulk deposition of Ge started several hundreds of mV positive from the solvent decomposition. Furthermore, distinct underpotential phenomena were observed. Some insight into the nanoscale processes at the electrode surface is given in Section 6.2.2.3. [Pg.304]

These results are quite interesting. The initial stages of Al deposition result in nanosized deposits. Indeed, from the STM studies we recently succeeded in making bulk deposits of nanosized Al with special bath compositions and special electrochemical techniques [10]. Moreover, the preliminary results on tip-induced nanostructuring show that nanosized modifications of electrodes by less noble elements are possible in ionic liquids, thus opening access to new structures that cannot be made in aqueous media. [Pg.307]

The electrochemically induced creation of the Pt(lll)-(12xl2)-Na adlayer, manifest by STM at low Na coverages, is strongly corroborated by the corresponding catalyst potential Uwr and work function O response to galvanostatic transients in electrochemical promotion experiments utilizing polycrystalline Pt films exposed to air and deposited on (T -AbCb. 3637 Early exploratory STM studies had shown that the surface of these films is largely composed of low Miller index Pt(lll) planes.5... [Pg.264]

The large size of CPOs allows their direct observation. For this purpose, scanning tunneling microscopy (STM) is the best method [32,34]. Electron microscopic analysis is used for phthalocyanine 3 and its derivatives however, most of the porphyrin derivatives are decomposed by electron beam irradiation. Presently, although only a limited number of researchers are able to perform atomic-scale resolution measurement, this powerful analytical method is expected to be used widely in the future. The author reported a summary of STM studies on porphyrins elsewhere [34]. [Pg.80]

STM studies of the Au(llO) surface indicated that only the Se (2x3) structure was formed at coverages much below one monolayer and that it was formed homogeneously. At monolayer and higher coverages, a honeycomb structure composed of chains of Se atoms was observed, which at still higher coverages filled in to complete a second Se layer. [Pg.176]

Suggs DW, Stickney JL (1993) Studies of the surface structures formed by the alternated electrodeposition of Cd and Te on the low-index planes of Au. II. STM studies. Surf Sci... [Pg.200]

Hayden BE, Nandhakumar I (1997) In-situ STM Study of Te UPD layers on low index planes of gold. J Phys Chem B 101 7751-7757... [Pg.200]

Dakkouri AS. 1997. Reconstmction phenomena at gold/electrolyte interfaces An in-situ STM study of Au(lOO). Solid State Ionics 94 99-114. [Pg.156]

Some conclusions that emerged in 1978 from the optical simulation study were as follows these could only be tested by (future) STM studies ... [Pg.17]

Simultaneously with the STM studies, Kulkarni et al,14 in Cardiff studied by XPS and HREELS the interaction of ammonia with Ni(l 10)-O and Ni(100)-0 surfaces. There was evidence in the N(ls) spectra for more than one nitrogen state present including N(a), but differentiating between NH(a) and NH2(a) was not possible. The intensity in the N(ls) spectrum region was broad over the range 397-400 eV. As the oxygen coverage increased to >0.3, the oxide O2 component became more prominent and the activity for ammonia oxidation decreased, as was observed by STM. Similar conclusions were reached for water interaction with the Ni(110)-O system.15... [Pg.84]

The STM study provided microscopic evidence for the participation of added silver atoms in the chemisorbed acetylide structure. The Ag(110)-p(2x 1)0... [Pg.94]

That chemisorbed oxygen was active in hydrogen abstraction, resulting in water desorption and the formation of chemisorbed sulfur, was first established by XPS at copper and lead surfaces.42 An STM study of the structural changes when a Cu(110)-O adlayer is exposed (30 L) to hydrogen sulfide at 290 K indicates the formation of c(2 x 2)S strings. [Pg.95]

In view of the spectroscopic evidence available, particularly from coadsorption studies (see Chapter 2), ammonia oxidation at Cu(110) became the most thoroughly studied catalytic oxidation reaction by STM. However, a feature of the early STM studies was the absence of in situ chemical information. This was a serious limitation in the development of STM for the study of the chemistry of surface reactions. What, then, have we learnt regarding oxygen transient states providing low-energy pathways in oxidation catalysis ... [Pg.99]

Since much of the impetus for our STM studies stems from earlier spectroscopic investigations of alkali metals and alkali metal-modified surfaces,6 we consider first what was learnt from the caesiated Cu(l 10) surface concerning the role of different oxygen states, transient and final states, in the oxidation of carbon monoxide, and then examine how structural information from STM can relate to the chemical reactivity of the modified Cu(110) surface. [Pg.104]


See other pages where STM studies is mentioned: [Pg.299]    [Pg.936]    [Pg.936]    [Pg.1682]    [Pg.1683]    [Pg.1684]    [Pg.1777]    [Pg.2757]    [Pg.2757]    [Pg.2941]    [Pg.2989]    [Pg.541]    [Pg.541]    [Pg.144]    [Pg.301]    [Pg.302]    [Pg.305]    [Pg.84]    [Pg.86]    [Pg.133]    [Pg.53]    [Pg.26]    [Pg.14]    [Pg.51]    [Pg.73]    [Pg.78]    [Pg.81]    [Pg.83]    [Pg.85]    [Pg.87]    [Pg.92]    [Pg.93]    [Pg.100]    [Pg.127]   
See also in sourсe #XX -- [ Pg.333 , Pg.334 , Pg.335 , Pg.336 ]




SEARCH



High pressure STM studies

In-Situ STM Study of Electrode-Aqueous Solution Interfaces

In-Situ STM Study of Electrode-Ionic Liquid Interface

STM

STM Studies of Anchoring Phase Transitions at Nematic Interfaces

Situ STM Studies of Model Catalysts

© 2024 chempedia.info