Ge crystal, prism 45 degrees, multiple reflection ( Harrick, Horizon) * attenuated total reflection (ATR) spectroscopy * reflection spectroscopy (PIKE variable angle specular reflectance accessory, angle of incident can varies from 30 to 80, different size of holes for samples) * polarization spectroscopy ( PIKE infrared polarizer) There are a number of ways in which we can accumulate spectra: The fact that their characteristic absorptions are often sensitive to local chemical environments makes this a powerful method for analysis of chemical bonds in materials. Many chemical bonds have resonances in the infra-red. Note that this technique is related to the more well-known secondary ion mass spectrometry technique but has the advantage that it is more sensitive since most of the material sputtered from a surface consists of neutral atoms rather than ions.įor further information on using this equipment for research please email Dr Behnam Akhavan or Dr Elena Kosobrodova.įTIR detects absorptions due to the vibrational modes of a sample in the infrared region of the spectrum. Detection limits of parts per million (ppm) can be achieved and unlike most other composition analysis methods, hydrogen can be analysed. The mass spectrum is directly related to the composition of the surface under analysis. These atoms are ionised and their mass to charge ratio is analysed in a mass spectrometer. A plasma is used to sputter etch the surface uniformly, releasing atoms from the sample.
Secondary Neutral Mass Spectrometry is a surface analysis technique complementary to XPS. Depth profiled measurements are also available. Elemental composition can be measured with a sensitivity of up to 0.1 atomic %. Our SPECS XPS system is equipped with sample manipulation, enabling samples to be transferred to and from other experiments, especially to and from our SNMS system. Not only are constituent elements identified in the spectrum but also their bonding conditions can be deduced. Surface analysis can be carried out by examining the energy distribution of the emitted photoelectrons. The energy of the photoelectrons depends on the element that released them and its chemical bonding environment. XPS uses a soft X-ray beam to eject photoelectrons from the surface of a specimen. the information is collected from the top 10 nm or so of the sample. X-ray photoelectron spectroscopy (XPS) can be used for investigating the surface chemistry of electrically conducting and non-conducting samples This technique has a sampling depth (sensitivity depth) of approximately 10 nm, i.e.
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