Oxide multi-elemental

As a second example, results from a TOP ERDA measurement for a multi-element sample are shown in Fig. 3.65 [3.171]. The sample consists of different metal-metal oxide layers on a boron silicate glass. The projectiles are 120-MeV Kr ions. It can be seen that many different recoil ions can be separated from the most intense line, produced by the scattered projectiles. Figure 3.66 shows the energy spectra for O and Al recoils calculated from the measured TOF spectra, together with simulated spectra using the SIMNRA code. The concentration and thickness of the O and Al layers are obtained from the simulations. 

The actual analysis of the samples started with a qualitative survey to identify the principal metals present. ICP-AES was selected as being most suitable for this because it provided a permanent record, a multi-element analysis, and good sensitivity. Solutions of the shellfish tissue were prepared for analysis by wet oxidation, and the sediments were digested with 40% v/v... 

At the Laboratory of the Government Chemist, increased analytical demands and the expense of suitable staff resulted in a requirement for the complete, or partial mechanization or automation of this kind of work. A review of the hterature, together with an examination of the procedures then used in the laboratory, suggested that a wet-oxidation system would be the most suitable for automation. This is described in detail here because it provides a valuable lesson in systems design. The specification of the automatic system was that it should be modular in construction in order to facifitate modification and maintenance, and that it should have a multi element capabihty. 

Spin-coating of Mixed Citrate Complexes as a Versatile Route to Prepare Films of Transition Metal Multi-element Oxide Model Catalysts with Controlled Formulation and Crystalline Structure... 

The principle of this process is shown schematically in Fig. 7 a. Mass spectrometry of the secondary ions provides a sensitive multi-element analysis of fresh surfaces. Figure 7 b shows the spectrum of a vanadium surface containing zirconium near the surface. With a current intensity of 5x I0 A a surface area of 0.1 cm was bombarded with 3 keV Ar" ions. Only 100 seconds were required for recording of the spectrum. In this time a monomolecular layer of vanadium oxide was analyzed which corresponds to a weight of about 10" g. Zirconium in the surface is identified by registration of the mass lines 90, 91, 92 and 94. These lines represent the naturally occuring isotopes of this group IV a element. In the secondary ion... 

Fuel Storage. In dedicated storage ponds in either skips (Magnox/AGR) or Multi-Element Bottles (MEBs-oxide fuels) ... 

The structural label perovskite applies to an enormous number of multi-element oxides. The ideal perovskite (CaTiOa) structure is cubic with one formula unit per unit cell, with ions on the body center (Ca), cube comers (Ti) and face centers (O). Identification of crystal structures as distortions (tetragonal, orthorhombic, trigonal) of this has allowed extension of the class even to the wedding-cake layer structures of the high-To superconductors (see, e.g., Phillips 1989). The properties of rare-earth perovskites (prior to the discovery of high-Tc s) are reviewed by Khattak and Wang (1979). 

Corrosion is a multifaceted process in lubricants. In situ corrosion sensors are most practicably to be contained within a multi element sensor array. Different sensors in the array could monitor the oxidation of various metals the lubricant comes into contact with, the conductivity of the fluid, while other sensors could monitor the TAN/TBN of the fluid. 

Ion chromatography can also be applied for ultra-trace analysis of transition metals. In comparison to ICP-MS it offers the advantageous ability to specify the oxidation state of metals and, moreover, to carry out multi-element determinations in the lowest ng/L range after pre-concentration. Transition metal separation is performed with ion exchangers that have defined anion and cation exchange capacities detection is carried out photometrically after derivatization... 

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