TOF (Time of Flight) Chamber

This chamber is currently used to study the surface chemistry of large organometallic molecules that are of interest to the microelectronics industry.  The main analytical tools on this chamber are a quadrupole mass spectrometer, a time-of-flight mass spectrometer, an auger electron spectrometer, a cylindrical mirror electron energy analyzer, and an ion gun. This system also has capabilities for studying photochemistry.  Behind the chamber there is a Spectra Physics YAG laser with MOPO optics.  With this system we can get photons from the IR range all the way up to UV normally obtained by dye lasers.
 

A 3D TOFMS-TPD spectrum of MeCpIrCOD on a Rh surface. The initial temperature of the Rh sample  is 100 K and increases up to 700 K with the heating rate of 2.5 K/s. Each complete mass spectrum from 1 AMU to 385 AMU results from accumulation of 10000 scans every 0.6 s. This 3D TOFMS-TPD spectrum is constructed with 450 mass spectra acquired during a TPD experiment.The intensities over 50 AMU are magnified 15 times.

Horizontal cross sections at 151 K and 251 K  correspond to mass spectra at different temperatures during a TPD experiment. Two TOFMS spectra at different temperatures (top: 251 K, bottom: 151K) during a TPD experiment. Each spectrum results from accumulation of 10000 scans in 0.6 s. These spectra are horizontal cross sections of a 3D TOFMS TPD of MeCpIrCOD on an Rh surface. The intensities after 10 ms are multiplied by 15. The structure of MeCpIrCOD is shown in the middle. The fragment pattern around the molecular ion is expanded in the inset. The mass resolution m/Dm of the molecular ion peak  is 580.

Conventional 2D TPD spectra of major desorbing species. Consists of vertical cross sectional slices of the 3D TOFMS TPD spectrum at the masses marked. Vertical cross sections at 2 AMU, 18 AMU, and 28 AMU, equivalent to conventional 2D TPD spectra, show different desorption patterns. The maxima at 251 K in the high mass region are resulted from fragmentation of MeCpIrCOD during ionization.

STM (Scanning Tunneling Microscope)

The Scanning Tunneling Microscope (STM) is a highly sophisticated device that allows the operator to "see" individual atoms and molecules on a conducting surface by measuring the tunneling current between an individual atom or molecule and an atomically sharp tip. By imaging these surfaces one can observe various reconstructions on surfaces and the interactions of adsorbates on a molecular level.  Some of the work that is being done with this instrument is 1) the observation of new reconstructions on Si surfaces, and 2) the interaction of halide containing molecules on metal surfaces.  This STM also has the capability to image at variable temperatures (30-1200 K).