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The configuration of the ion beam apparatus can be changed and made more complex with the incorporation of additional components. The techniques for ion beam analysis are designed for specific purposes. Some techniques and ion sources are shown in table 1. Detector types and arrangements for ion beam techniques are shown in table 2.
Once the ion beam has ionized target sample atoms, the sample ions are recoiled toward the detector. The beam ions are scattered at an angle that does not permit them to reach the detector. The sample ions pass through an entrance window of the detector, and depending on the type of detector used, the signal is converted into a spectrum.
Rutherford backscattering spectrometry (RBS) is an analytical technique used in materials science.Sometimes referred to as high-energy ion scattering (HEIS) spectrometry, RBS is used to determine the structure and composition of materials by measuring the backscattering of a beam of high energy ions (typically protons or alpha particles) impinging on a sample.
As the diagram on the right shows, the gallium (Ga+) primary ion beam hits the sample surface and sputters a small amount of material, which leaves the surface as either secondary ions (i+ or i−) or neutral atoms (n 0). The primary beam also produces secondary electrons (e −). As the primary beam rasters on the sample surface, the signal ...
The technique can be used in line profiling of the elemental composition across the surface, or in depth profiling when paired with ion-beam etching. It is often applied to study chemical processes in the materials in their as-received state or after cleavage, scraping, exposure to heat, reactive gasses or solutions, ultraviolet light, or ...
Often the detector is a simple Faraday plate coupled to a transimpedance amplifier, however, more advanced ion mobility instruments are coupled with mass spectrometers in order to obtain both size and mass information simultaneously. It is noteworthy that the detector influences the optimum operating conditions for the ion mobility experiment. [32]
Axial bright-field detectors are located in the centre of the cone of illumination of the transmitted beam, and are often used to provide complementary images to those obtained by ADF imaging. [12] Annular bright-field detectors, located within the cone of illumination of the transmitted beam, have been used to obtain atomic resolution images ...
This is the method used in the original discovery of X-ray diffraction. Laue scattering provides much structural information with only a short exposure to the X-ray beam, and is therefore used in structural studies of very rapid events (time resolved crystallography). However, it is not as well-suited as monochromatic scattering for determining ...