Ultra high direct transfer systems

The methodology of surface electrochemistry is at present sufficiently broad to perform molecular-level research as required by the standards of modern surface science (1). While ultra-high vacuum electron, atom, and ion spectroscopies connect electrochemistry and the state-of-the-art gas-phase surface science most directly (1-11), their application is appropriate for systems which can be transferred from solution to the vacuum environment without desorption or rearrangement. That this usually occurs has been verified by several groups (see ref. 11 for the recent discussion of this issue). However, for the characterization of weakly interacting interfacial species, the vacuum methods may not be able to provide information directly relevant to the surface composition of electrodes in contact with the electrolyte phase. In such a case, in situ methods are preferred. Such techniques are also unique for the nonelectro-chemical characterization of interfacial kinetics and for the measurements of surface concentrations of reagents involved in... 

The pertinent operating conditions were as follows samples are placed on a sample holder 1 cm in diameter and transferred via a railway system and vacuum lock from atmospheric pressure to ultra high vacuum within thi p minutes approximately. The base pressure of the system was 10 but conventional operational pressure was approximately 10 Torr of argon. A precision manipulator allowed the movement of the sample in X, Y and Z directions within the chamber. A mass filtered beam of argon atoms (0.5-2 keV) was... 

A common feature of all of these methods is that measurement is carried out in ultra-high vacuum (UHV) (<10 torr) thus any electrode surface to be examined must be removed from the cell, possibly rinsed, dried of solvent, and then place in vacuo. Electrodes cannot be examined in situ, since liquids will absorb and block the beams of electrons and ions. The sample must be transferred into a system where there is no electrolyte. This always raises the possibility that the analyzed interface differs significantly from the one in the cell, which is the actual point of interest. For example, hydrated solids will lose water in vacuum and may change composition. Also, exposure of the electrode to the air during transfer can cause oxidation of surface species. Special apparatus has been designed to minimize the problems of exposure to the atmosphere by allowing the sample to be removed from the cell in an inert atmosphere and moved directly into the UHV (Figure... 

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