Infrared spectroscopy

Infrared is commonly used to:

• Identify inorganic compounds, including minerals
• Quantify H₂O, OH^-, CO₂, CO₃^2- and SO₄^2- in solids like minerals and glasses
• Determine the spectral signatures of materials relevant to remote sensing
• Quantify functional groups in pharmaceutical, agricultural, medical and manufactured materials
• Identify historical art media and archaeological artifacts

Top reasons to use IR:

• Useful for molecules with a dipole moment like polar groups, substituents on organic molecules, bonds in solids (e.g., Si-O, Al-O, B-O, H-O, C-O, C-H, N-O, S-O)
• Samples can be crystalline, microcrystalline, amorphous or liquid
• Very small samples can be analysed (<6μm lateral resolution)
• Fast (1-10 minutes)
• Qualitative ID is straightforward
• Quantitative molecular abundances may be determined

FTIR spectrometer with microscope & mapping stage

• Mid-IR: 400-5600 cm^-1 (1.8-25 μm)
• Reflectance, transmittance and attenuated total reflectance
• Dry air purge
• Microscope (15x and 36x objectives) with mapping stage that provides automated collection of spectra with ≥ 1μm step over 1cm²

Environmental chamber

• Diffuse reflectance in a controlled-temperature reaction chamber
• -150 to 500ºC
• Vacuum or gas flow
• Analysis of powders and reaction products (including surface species) in situ during experiments

Small-scale environmental chamber

• Environmental stage for in situ transmission or reflectance IR micro-analyses
• -196 to 900ºC with vacuum or gas flow

Field equipment

Portable or mounted FTIR

• Reflectance, grazing angle and attenuated total reflectance analysis
• Rapid analysis of powders, films and flat surfaces
• Used in the field or lab

Geochemical and field equipment

• Multi-meter with probes for measuring pH, ionic species, conductivity, dissolved O₂, total dissolved solids, temperature and barometric pressure
• Humidity-temperature data loggers

X-ray diffraction laboratory

Bragg-Brentano & transmission diffractometers

• Powders or flat solid samples (>1μmg)
• Phase identification and quantification including clay minerals
• Crystal structure (Rietveld) refinement

Thermal analysis equipment

• Thermogravimetric analyser <1200ºC
• Differential thermal analyser <1200ºC
• Differential scanning calorimeter <725ºC

Materials preparation facility

• Horizontal tube furnaces (<1650ºC)
• High-temperature box furance + ovens

Current projects include:

• In situ analyses to characterise reactions as a function of temperature and gas atmosphere
• Detecting rock art coatings appropriate for dating
• Spatially mapping water diffusion in crystals and glasses
• In situ temperature-dependent reaction rates
• Investigating relationships between silicate glass structure, composition, thermal effects and spectra