Chalcogenide glass chemical

Vlasov YG, Bychkov EA, Legin AV (1994) Chalcogenide glass chemical sensors Research and analytical applications. Talanta 41 1059-1063... 

Research and development of chalcogenide glass chemical sensors are gaining more attention. Analytical applications of this type of sensors for environmental monitoring and process control have been reported for the detection of microgram levels of copper (II), iron (III), chromium (VI), lead, cadmium and mercury in natural and waste waters (27,28). In addition, the applications of chalcogenide glass sensors for laboratory analysis, industrial control and... 

Compared to the corresponding polycrystalline metal chalcogenides, chalcogenide glasses exhibit better chemical stability in acidic and redox media and often... 

Figure 4.26. The three possible tetrahedral Si configurations in chalcogenide glasses and the corresponding Si chemical shifts in sulphide and selenide glasses. Adapted from Moran et al.

The earliest ° T1 NMR solid state studies were of the common thallium salts in both the solid phase and the melt, and of thallium silicate, borate and chalcogenide glasses. The ° T1 NMR literature up to 1988 has been extensively reviewed by Hinton et al. (1988). The chemical shift data for a number of thallium compounds are presented in Table 9.11. In view of the large CSA values which can occur in T1 compounds, distortion of the lineshapes can occur by loss of signal during the probe deadtime. Some of the earlier ° T1 NMR data may be corrupted in this way, and should be treated with caution. 

Chemical nature of photoresists, the chemistries involved in the photolithography, the properties of photoresists are briefly described. The discussion includes diazonaphthoquinone/novolac positive photoresists, polymer-aromatic diazide negative photoresists, photopolymerizable compositions, chalcogenide glass using systems, chemically amplified photoresists, and photoresists with an image formation in a thin layer. 

The last three chapters summarize unique structural and chemical features of a variety of glasses. They also provide an overview of the important aspects of the glass systems. Chapters 12 and 13 discuss respectively oxide and chalcogenide glasses particularly in view of their chemistry, structure and a number of special phenomena associated with them. In chapter 14, synthesis, structure and properties of halide, oxyhalide, oxynitride and metallic glasses are discussed. Some aspects of glass-like carbon have also been presented. 

Infrared spectrometry is currently exploited in process analysis but less so than near IR and Raman spectrometry. The reasons for this are the strong absorbances of most mid IR bands and the sensitivity of mid IR optical materials to chemical erosion. There is also a relative lack of practical hbre optic options for use in the mid IR range since silver halide and chalcogenide glasses, which cover the whole of the mid IR region, can attenuate the radiation by as much as 95%, even over short distances. Other hbres such as zirconium fluoride cut off below 2500 cm and so the fingerprint region information is lost. 

The source of the silver in this system is the Ag2Se, formed as a thin layer on the surface of the Ge Sej- , (i.e., GeSe2-Sey) chalcogenide glass by a chemical reaction in a bath containing Ag(CN) anions according to... 

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