Perrine Research Equipment
Surface science provides the foundation for understanding chemical mechanisms and physical transformations on surfaces. Multiple surface analytical techniques are needed to fully understand interfacial chemical reactions by answering questions such as:
- how adsorbates react with surfaces
- what the identities are of surface intermediates
- what products evolve from the surface
- how does the surface changes during a reaction
Surface science has evolved from measuring reactions under controlled conditions in ultra high vacuum (UHV) towards high pressure conditions, while retaining surface sensitivity. Low pressures are needed to controllably introduce a reactant (in the gas phase) to a surface. This is fulfilled by having a low base pressure in order to prevent undesired interactions (from air) with the surface. Modern surface science has shifted that pressure regime towards reaction conditions, while still retaining the surface sensitivity in the measurement process. The spectroscopies on the Surface Analysis instrument will determine how adsorbates and their intermediates transform on a surface.
The Perrine Research Group Surface Analysis Instrument includes:
*located at 615 Minerals & Materials Building
A surface sensitive FTIR technique that allows one to polarize the infrared light and select the surface active species through reflection at a grazing angle. Using this technique allows measurement of surface reactions near ambient pressures – near real reaction conditions. The surface intermediates are also detected by measuring the FTIR spectra at different temperatures or as a function of light exposure, for photo-stimulated mechanisms.
Auger Electron Spectroscopy (AES)
AES is an electron spectroscopy technique that allows measurement of the chemical state and chemical binding of elements on the surface before and after surface adsorption. The AES process involves ejecting a secondary electron from core-levels using electron emission.
Temperature Programmed Desorption (TPD)
TPD utilizes a mass spectrometer to detect the partial pressures of the mass fragments, from molecular adsorbates, that desorb from a surface. The desorption peak and the shape of the desorption curve yield information on the desorption kinetics, surface sites and reaction mechanisms. This technique is highly complementary to PM-IRRAS in the UHV regime, as the infrared spectra produced can yield surface intermediates and the TPD experiments will yield desorption mechanisms.
Chemical Wet Lab
Laboratory space for ex-situ sample preparation. This space includes 2 hoods, bench top space, furnaces, flammable storage cabinet and extra vacuum equipment. *located at 711 Chemical Sciences and Engineering Building
Instruments we are connected with and use at Michigan Technological University
XPS is a surface science techniques that measures surface composition of both the surface material and adsorbed molecules, including binding energies and electronic properties. The PHI 5800 XPS in ACMAL is equipped with a dual source anode (Al and Mg), a hemispherical analyzer, for XPS and AES analysis, including elemental mapping capabilities, an electron gun source for AES analysis, an ion sputter gun for depth profiling, a heatable sample stage, and stage tilting for angle-resolved XPS. The XPS was generously donated by the Army Research Laboratories with help from the Department of Chemistry at Michigan Tech. *located at 6th floor Minerals & Materials Building
Atomic Layer Deposition (ALD)
ALD is a growth technique that allows for chemical growth of materials one atomic layer at a time. A metal-organic reactant and an oxidative co-reactant are used to deposit clean, conformal films on substrates. This technique is used to grow tailored architectures for unique materials for the next-generation heterogeneous catalytsts or as model platforms for environmental studies. This instrument is currently being refurbished by the Microfabrication Facility and added to their suite of instruments for our use. *located at 436 Minerals & Materials Building
Facilities we use at Michigan Technological University
The Applied Chemical and Morphological Analysis Laboratory (ACMAL) is a University Shared Facility which is part of the Materials Characterization & Fabrication Facilities. ACMAL houses an extensive array of electron microanalytical and X-ray instruments. ACMAL is managed by the Department of Materials Science and Engineering. *located at 6th floor Minerals & Materials Building
The Microfabrication Facility (MFF) is Michigan Tech’s resource for micro- and nano-scaled research and development of solid state electronics, micro electro mechanical systems (MEMS), and microsystems materials and devices. The ALD instrument will be added to the suite of instruments in the MFF. *located at 4th floor Minerals & Materials Building
Instruments that are available within the Department of Chemistry at Michigan Tech: