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UHV - Ambient Pressure RAIRS System

RAIRS Chamber


Our new high pressure RAIRS system contains two separate chambers for low and high pressure analysis.  The main chamber is a typical UHV analysis chamber equipped with a quadrupole mass spectrometer (Prisma QMS200 from Pfeiffer), and a combined reverse-view low energy electron diffraction (LEED)- Auger electron spectrometer (AES) system from LK technologies (Series RVL2000).  The two instruments share a common electron gun that is retractable for better positioning in the chamber.  A CMA2000 electron energy analyzer is used for the AES experiments.

The high pressure IR cell is located underneath the main chamber.  It is equipped with a Bruker Vertex 70v FTIR; when performing a high pressure experiment, the crystal is passed through a differentially pumped sliding seal system into the high pressure cell. With the crystal at the IR focus, the sample probe seals off the upper UHV chamber from the high pressure IR cell.

The low pressure in the main chamber is maintained by a turbo pump (Pfeiffer PM P02825), a titanium sublimation pump (Duniway TSP-275-00), and an ion pump (Varian 9192641M001).


RAIRS System



This chamber is equipped with an FTIR (Bruker IFS-66v/s) for RAIRS studies, a quadrupole mass spectrometer (Hiden HAL 201/3F) interfaced to a personal computer for temperature programmed desorption (TPD) studies, a single-pass cylindrical mirror analyzer (Physical Electronics Model no. 10-155), and LEED optics (Physical Electronics 15-180). It is pumped with a turbo-molecular pump (Leybold-Heraeus TMP 360) backed by a diffusion pump. It has all of the ancillary valves, vacuum gauges, sample manipulator, gas doser, sputter ion gun, etc., needed for surface science studies of reactive chemistry on transition metal surfaces.




UHV Scanning Probe Microscopy System



This variable temperature UHV Scanning Probe Microscopy system was manufactured by Omicron Nanotechnology GmbH ( It was purchased as a complete system and is equipped with a combined STM/AFM unit with a sample stage that permits images to be obtained, in principle, over the temperature range of 25 to 1500 K.  The system is also equipped with a reverse view LEED instrument and with a metal evaporator. The STM uses a standard tube scanner with an electrochemically sharpened metal tip whereas AFM images are obtained with a needle-sensor based on a miniature quartz resonator.  Sample introduction and tip exchange are achieved without breaking vacuum using a load lock system.  The STM tip and AFM needle-sensor are readily interchangeable.  The capabilities of the STM function of this instrument is demonstrated by images of the Si(111)-7x7 surface obtained by our group.






In addition to a dedicated FTIR (Mattson RS-10,000) for RAIRS studies, this chamber is equipped with reverse-view LEED optics (Princeton Research Instruments RVL 8-120), a quadrupole mass spectrometer (UTI Instruments 100C) that is fully computer controlled for multiplexed TPD studies, and a hemispherical electron energy analyzer (VG Scientific CLAM 2) and a dual Mg/Al anode X-ray source (VG Scientific) for XPS studies. The chamber is pumped by a turbo-molecular pump (Balzers TMP 520). The FTIR was purchased in 1984 from Mattson and has been upgraded with new electronics and software and is now controlled by a standard low cost personal computer. Although the RAIRS-2 chamber is completely independent of the separately described RAIRS-1 chamber, certain items such as IR detectors and polarizers are shared, to some extent.



Scanning Tunneling Microscopy System

In addition to a UHV STM, this chamber is equipped with reverse-view LEED optics (Princeton Research Instruments RVL 8-120), a qstm1uadrupole mass spectrometer (UTI Instruments 100C) that is fully computer controlled for multiplexed temperature programmed desorption (TPD) studies, and a hemispherical electron energy analyzer (VG Scientific CLAM 100) combined with a dual Mg/Al anode X-ray source (VG Scientific) for XPS studies. Using an electron gun the same analyzer is used for electron stimulated Auger electron spectroscopy. The chamber is pumped by a turbomolecular pump (Leybold Heraeus TMP 150), an ion pump (Varian Associates, Inc., 230 l/s Starcell), and a Ti-sublimation pump. The turbo pump can be isolated from the main chamber by a gate valve and turned off during STM studies. The chamber pressure is read with Bayard Alpert nude ion gauges (Granville Phillips Co. series 274). The chamber rests on a vibrational isolation platform (Barry Control, Inc.). The STM used in this study is a UHV compatible commercial instrument (McAllister Technical Services) employing a segmented piezo ceramic cylinder as the scanning element. The one inch tube allows images of up to one micron square to be obtained. The scanning tube is surrounded by a larger piezo cylinder bonded to a quartz section, which in turn supports two tungsten carbide rods on which the sample holder sits. Sample approach to the tip is accomplished inertially under computer control by applying a sawtooth wave-form to this larger piezo tube. The chamber is configured for sample transfer via a wobble stick between a fully rotatable XYZ manipulator and the STM. The XYZ manipulator has a sample stage that can be cooled with liquid nitrogen. The wobble stick also allows for transfer of samples to and from a storage rack, which enablesup to six samples to be present at once in the UHV chamber. The STM contains a rack for storage of 8 tips, each of which can be cleaned by heating within the UHV chamber by electron bombardment.


Scanning Auger Multiprobe System - For Sale -
Contact RBD Instruments or the Trenary Group directly for Details
Link: RBD Instruments



The Perkin-Elmer Scanning Auger Microprobe 600 is a complete system containing several instruments and all of the pumps, gauges, valves, etc., needed for independent operation. The main instrument is a cylindrical mirror analyzer with coaxial electron gun. The electron gun (equipped with a LaB6 cathode) can be focused to a beam size of 350 Å at a beam current of 0.1-.01 nA. The beam can be rastered over the sample with the electron energy analyzer tuned to a particular element. In this way, one can obtain a two-dimensional map of an elemental distribution across a surface. The scanning capabilities of the beam can be used with a secondary electron detector to obtain scanning electron microscope (SEM) images of a surface. The system also contains an ion gun for Auger depth profile measurements and a quadrupole mass spectrometer for secondary ion mass spectroscopy (SIMS). This system was purchased by the Amoco Research Center in Naperville, IL in 1985 and was donated UIC in 1995. Since then, the instrument has been enhanced in various ways including upgrades of the computer and computer interface.





Chemistry Department

Chemistry Department

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Professor Michael Trenary
Phone: (312)996-0777