Optical emission spectroscopy OES

The original OES instruments, dating from the 1930s but used consistently from the 1950s, used a spark source to excite the emission spectrum, which usually consisted of a graphite cup as one electrode, and a graphite rod as the other. The sample (solid or liquid) was placed inside the cup and the graphite rod lowered until it was close to the cup. The sample was then vaporized by 

The instruments designed for these analyses comprise several parts the device responsible for bringing the sample in the form of excited or/and ionized atoms (based on gas plasmas, sparks or lasers), an high quality optical bench which conditions the analytical performances, a detector with a sensor (PMT or diode 

Chemical Analysis Second Edition Francis and Annick Rouessac 

The characteristic that most distinguishes these spectrometers from AA or FE instruments is their optical bench and sometimes their impressive size. They are reserved to analytical laboratories that have to treat a great deal of samples. 

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In order to relate material properties with plasma properties, several plasma diagnostic techniques are used. The main techniques for the characterization of silane-hydrogen deposition plasmas are optical spectroscopy, electrostatic probes, mass spectrometry, and ellipsometry [117, 286]. Optical emission spectroscopy (OES) is a noninvasive technique and has been developed for identification of Si, SiH, Si+, and species in the plasma. Active spectroscopy, such as laser induced fluorescence (LIF), also allows for the detection of radicals in the plasma. Mass spectrometry enables the study of ion and radical chemistry in the discharge, either ex situ or in situ. The Langmuir probe technique is simple and very suitable for measuring plasma characteristics in nonreactive plasmas. In case of silane plasma it can be used, but it is difficult. Ellipsometry is used to follow the deposition process in situ. 

Knowledge on the plasma species can be obtained by the use of plasma diagnostics techniques, such as optical emission spectroscopy (OES) and mass spectroscopy (MS). Both techniques are able to probe atomic and molecular, neutral or ionized species present in plasmas. OES is based on measuring the light emission spectrum that arises from the relaxation of plasma species in excited energy states. MS, on the other hand, is generally based on the measurement of mass spectra of ground state species. 

Optical elements, liquid crystalline materials in, 15 116—117 Optical emission spectra, 14 833-837 plutonium, 19 671—673 Optical emission spectroscopy (OES), archaeological materials, 5 742 Optical fiber(s), 13 391-392 24 618 defects in, 11 145 drawing of, 11 141-145 fabrication of, 11 135-141 health care applications for, 13 397 overcladding of, 11 144 remote measurements using, 14 234 in sensors, 22 270-271 sol-gel processing of, 11 144-145 strength of, 11 141-145 vitreous silica in, 22 444 Optical fiber sensors, 12 614-616 Optical germanium, 12 556... 

The development of instrumental measurement techniques during the 1920s and 1930s such as optical emission spectroscopy (OES see Section 3.1) gave... 

Since the mid-1960s, a variety of analytical chemistry techniques have been used to characterize obsidian sources and artifacts for provenance research (4, 32-36). The most common of these methods include optical emission spectroscopy (OES), atomic absorption spectroscopy (AAS), particle-induced X-ray emission spectroscopy (PIXE), inductively coupled plasma-mass spectrometry (ICP-MS), laser ablation-inductively coupled plasma mass spectrometry (LA-ICP-MS), X-ray fluorescence spectroscopy (XRF), and neutron activation analysis (NAA). When selecting a method of analysis for obsidian, one must consider accuracy, precision, cost, promptness of results, existence of comparative data, and availability. Most of the above-mentioned techniques are capable of determining a number of elements, but some of the methods are more labor-intensive, more destructive, and less precise than others. The two methods with the longest and most successful histoty of success for obsidian provenance research are XRF and NAA. 

The direct evidence to show that reactive species are created in the dissociation glow rather than in the ionization glow was found in the in situ Optical Emission Spectroscopy (OES) analysis aimed specifically at the dissociation glow and at the ionization glow of TMS DC discharge in a closed system [4]. Figures 4.4 and 4.5... 

The most utilized methods include X-ray fluorescence (XRF), atomic absorption spectroscopy (AAS), activation analysis (AA), optical emission spectroscopy (OES) and inductively coupled plasma (ICP), mass spectroscopy (MS). Less frequently used techniques include ion-selective electrode (ISE), proton induced X-ray emission (PIXE), and ion chromatography (IC). In different laboratories each of these methods may be practiced by using one of several optional approaches or techniques. For instance, activation analysis may involve conventional thermal neutron activation analyses, fast neutron activation analysis, photon activation analysis, prompt gamma activation analysis, or activation analysis with radio chemical separations. X-ray fluorescence options include both wave-length and/or energy dispersive techniques. Atomic absorption spectroscopy options include both conventional flame and flameless graphite tube techniques. 

The first half of the twentieth century saw a series of new studies, often using technologies that resulted from the military research driven by world wars. The introduction of instrumental methods such as optical emission spectroscopy (OES) initiated several major research programs concerned with the origins of bronze in Europe. The new instruments meant a large number of samples could be measured. Thousands of bronze objects in Europe were analyzed in these studies (e.g., Caley 1964 Junghans et al. 1960). 

Plasma was characterized using Optical Emission Spectroscopy (OES). The OES optical fiber was placed 5 cm above the porous plate. 

The most direct need for plasma diagnostic techniques results from the determination of the etch end point for a given process. In addition, plasma diagnostic techniques are used for process monitoring and provide information on the types of species present in a plasma etching, the concentration, and the energy content. Laser interferometry (or reflectance) and optical emission spectroscopy (OES) are two commonly used techniques for EPD and require only an appropriate optical window attached to the chamber. They are easily implemented to obtain information about etching plasmas [1]. 

Inductively coupled plasma (ICP) ionization has currently assumed a more prominent role in the field of elemental and isotopic analysis [1,2,14]. It is apphcable to solid-state as well as to solution-phase samples. A plasma is defined as a form of matter that contains a significant concentration of ions and electrons. The heart of this technique is a plasma torch, first developed as an efficient source for optical emission spectroscopy (OES) [15,16]. Multielement analysis with OES has, however, some serious shortcomings, such as complicated spectra, spectral interferences, high background levels, and inadequate detection of some rare-earth and heavy elements. The high ionization efficiency (>90%) of ICP for most elements is an attractive feature for its coupling to mass spectrometry. 

In metallurgy, alloy composition can be rapidly determined and unknown samples identified rapidly. XRF has an advantage over wet chemistry in that all the components can be measured due to the wide dynamic range of XRF. For example, in the analysis of nickel alloys, a wet chemical approach would measure all the other elements and calculate the Ni content as the balance. With XRF, the major element, nickel, as well as the minor and trace components can be measured accurately. For high-grade steel and alloys with multiple major components, WDXRF achieves better accuracy and repeatability than optical emission spectroscopy (OES). 

Example 5.1. The following calibration results were obtained for the determination of Ni in WO3 by optical emission spectroscopy (OES) ... 

Maity techniques exist for examining the composition of the species (including radical species) generated in CVD reactors optical emission spectroscopy (OES) [80], FT-IR spectroscopy [81] laser induced fluorescence (LIE) spectroscopy [82], diode laser IR absorption spectroscopy [83], and MS [84-87]. Each has its own strengths and shortcomings. A major advantage of MS over other techniques is its... 

Optical emission spectroscopy (OES) The technique of measuring the ophcal emission from a plasma. Used to determine the species and density of pardcles in a plasma. 

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