Glossary terms about Ion
- Ion
- An atom, or group of atoms, that has lost one or more electrons making it positively charged (a cation) or gained one or more electrons making it negatively charged (an anion).
▼25 more terms contain Ion
- Ion
- An atom, or group of atoms, that has lost one or more electrons making it positively charged (a cation) or gained one or more electrons making it negatively charged (an anion).
- Precision
- The reproducibility of the analysis based on statistics related to the number of counts in the X-ray spectrum.
- Absorption
- X-ray absorption is most commonly due to the photo-electric effect. An X-ray photon is absorbed by an atom and a photo-electron is emitted.
- Relaxation
- Recovery of the atom to a stable state following ionization, by emission of a Characteristic X-ray or an Auger electron.
- Detection limit
- The lowest amount of an analyte in a sample that can be detected but not necessarily quantified
- ZAF corrections
- Matrix corrections based on differences in atomic number (Z), absorption (A) and fluorescence (F) between the sample and standards.
- Ionization energy
- The energy required to remove an electron from a stable shell or subshell.
- Siegbahn notation
- The most commonly used convention for naming Characteristic X-ray lines based on the shell of the element that is ionized and the relative intensity of the Characteristic X-ray that is produced.
- X-ray diffraction (XRD)
- X-ray diffraction: a technique for identifying materials and characterizing their crystal structure by measuring the intensities of X-rays diffracted by the sample.
- Matrix corrections
- Corrections applied to the measured raw intensities of X-ray peaks to allow for differences in composition between the sample and the standards.
- Region of interest
- A defined energy range in the energy dispersive spectrum, usually corresponding to the energy of a Characteristic X-ray peak for mapping.
- Resolution - spatial
- In microanalysis, the size of the smallest particle that can be analysed.
- Electron diffraction (ED)
- Electron diffraction: a technique for identifying the structure of a sample by examining the diffraction patterns produced by scattering of an electron beam by the sample in a TEM.
- Resolution - spectral
- In microanalysis, the width of a characteristic X-ray peak measured in either energy (eV) or wavelength (nm), at half the maximum peak height.
- Inner shell ionization
- Removal of an electron from an inner (K, L or M) electron shell. The atom is in an excited state.
- Micro-X-ray diffraction (m-XRD)
- An in situ microbeam technique based on X-ray diffraction spectroscopy.
- Pulse pile-up correction
- The process of removing spectral artifacts from the energy dispersive spectrum and returning the counts to the channels where they should have been recorded.
- Critical ionization energy
- The energy required to remove an electron from a stable shell or subshell.
- Mass Absorption Coefficients (MAC)
- A matrix of numbers reflecting the absorption of a particular X-ray line (the emitter) by all the other elements in the periodic table.
- Particle induced X-ray emission (PIXE)
- Particle induced X-ray emission: the sample is bombarded with a beam of particles (He ++ ions), with emission of Characteristic X-rays, but little or no Bremsstrahlung X-rays.
- Secondary ion mass spectrometry (SIMS)
- Secondary ion mass spectrometry: a technique for measuring isotopes and trace element compositions of a sample. A primary ion beam ablates the sample to produce a beam of secondary ions. The secondary ions are analysed by a mass spectrometer.
- Micro-particle-induced X-ray emission (m-PIX)
- An in situ microbeam technique based on particle induced X-ray emission.
- Instrumental neutron activation analysis (INAA)
- Instrumental neutron activation analysis
- Time-of-flight secondary ion mass spectroscopy (TOF-S)
- Time-of-flight SIMS: a technique for surface analysis that focusses a beam of primary ions on the sample and measures secondary ions sputtered from the surface to provide information about molecular and elemental species.
- Inductively coupled plasma - optical emission spectrometry (ICP-O)
- Inductively coupled plasma - optical emission spectrometry: a wet sample technique in which a solution is introduced to an argon plasma at 8000?C. The elements emit light of characteristic wavelengths which is analysed by a spectrometer.
- Laser ablation - inductively coupled plasma - mass spectrometry (LA-IC)
- Laser ablation - inductively coupled plasma - mass spectrometry: a technique for measuring isotopes and trace element compositions in a sample. A laser is used to ablate material from the sample, which is transported to an inductively couples argon plasma. The plasma generates ions that are then analysed by mass spectrometer.
28 pages mention Ion
- Accuracy, Precision and Detection Limits
- It depends on the standards used and the spectral processing and corrections applied to the raw data.
- Additional material
- Microscopy & Microanalysis 12, 2–25.
2006.
Newbury D. Find Analytichem - The revolution in Energy Dispersive X-Ray Spectrometry: spectrum imaging at output count rates above 1MHz with the silicon drift detector on the scanning electron microscope.
- Auger animation
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Click the buttons below to view each stage.
- Background information - What is energy dispersive X-ray spectroscopy?
- Energy Dispersive X-ray Spectroscopy (EDS, EDX or XEDS) is a qualitative and quantitative X-ray microanalytical technique that can provide information on the chemical composition of a sample for elements with atomic number (Z) >3.
- Bremsstrahlung animation
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Click the buttons below to view each stage.
- Bremsstrahlung X-ray generation
- Two types of X-rays are produced by interaction of the electron beam with the sample in both the SEM and TEM: Bremsstrahlung (which means ‘braking radiation’) and Characteristic X-rays.
- Characteristic X-ray generation
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Click the buttons below to view each stage.
- Characteristic X-rays
- The K shell has the highest ionization energy or critical ionization energy in the atom.
- EDS spectral artifacts
- Improvements in design and construction of semiconductor detectors has minimized these artifacts, but they may be present in older detectors.
- EDS spectral resolution
- A Characteristic X-ray peak in an ED spectrum has a spectral resolution that is related to the width of the Gaussian peak and is a function of the detector that was used to collect the spectrum, and its electronics.
- Generation of X-rays in the Electron Microscope
- In the scanning electron microscope (SEM), the electrons from the primary beam spread out in the sample to form the interaction volume.
- Introduction
- This module will provide you with background information and practical advice for the successful operation of a range of microanalytical methods, with emphasis on techniques that are commonly hosted on SEMs and TEMs.
- K-lines animation
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Click the buttons to show each peak.
Show CShow SShow Ca
The Kα X-ray peak for carbon (Z=6)
- KL-lines animation
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Click the buttons to show each peak.
Show ScShow Zn
For scandium (Z=21) the Kα and Kβ peaks are resolved and L-family peaks are visible at low energy.
- L-lines animation
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Click the buttons to show each peak.
Show RbShow TcShow Sb
For rubidium (Z=37) the Ll peak can be seen on the low-energy side of the main L-family peak.
- M-lines animation
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Click the buttons to show each peak.
Show HfShow PbShow U
For hafnium (Z=72) the Mζ peak (low energy) and Mγ peak (high energy) can be seen on either side of the main M family peak.
- Operational example - area and map analysis - stainless steel
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- Operational example - point analysis - stainless steel
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- Operational example - project setup - stainless steel
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- Qualitative EDS X-ray microanalysis using SEM and TEM
- While commercial peak-identification software is improving all the time, it is not yet 100% accurate.
- Quantitative EDS X-ray microanalysis using SEM
- In quantitative EDS microanalysis in SEM, the mass fractions or weight percents of the elements present in the sample are calculated.
- Reference standard
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- The photoelectric effect
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- Virtual area analysis with mapping - granite
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- Virtual point analysis - granite
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- X-ray detection by EDS
- Other detection systems, e.
- X-ray intensity
- It is tempting to assume that the height of the X-ray peak in the spectrum will be proportional to the concentration of the element in the sample.
- X-Ray mapping
- X-ray mapping provides images of elemental distributions in a sample.