Ion optical properties

In practice, the ion optical properties of an ion source are optimized by means of ion trajectory calculations. [31] The standard tool for this task is the SIMION software suite, [32-35] while there are others, too. [36] Thus, the optimum number, positions, voltages, and eventually shapes of the plates are determined (Fig. 5.11). In order to compensate for slight mechanical deviations from theory and for effects exerted by contamination of the plates during elongated use, the voltages can be adjusted to yield optimum conditions. 

D. Ioanoviciu, Ion-optical properties of time-of-flight mass spectrometers, Int. J. Mass Spectrom., 206 (2001) 211-229. 

Figure 6.8 Sketch of the mode of action of an Einzel lens. This is a simple example in which the three lens elements are flat plates providing focusing in only one of the directions perpendicular to the main ion beam axis. The ions are assumed to be positively charged, and thus experience forces in the directions indicated on the field lines, i.e., contrary to naive expectations, these positive ions are first deflected towards the central element held at a positive potential, but are subsequently re-directed to the central axis. It is the shapes of the field lines that determine the ion optical properties.

Orbach, Optical Properties of Ions in Solids, Plenum Press, New York, 1975, p. 370. 

H. M. Crosswhite andH. W. Moos, eds.. Optical Properties of Ions in Crystals, Wiley-Interscience, New York, 1967. D. Curie, Euminescence in Crystals, Methuen, London, 1963. 

Low temperature sol-gel technology is promising approach for preparation of modified with organic molecules silica (SG) thin films. Such films are perspective as sensitive elements of optical sensors. Incorporation of polyelectrolytes into SG sol gives the possibility to obtain composite films with ion-exchange properties. The addition of non-ionic surfactants as template agents into SG sol results formation of ordered mechanically stable materials with tunable pore size. 

The direct imaging magnetic sector mass analyzer (Fig. 3.19) has the unique property that all parts (lenses, electrostatic analyzer and magnetic sector field) of the secondary ion optics are stigmatic (comparable with light microscopes). This means that all points of the surface are simultaneously projected into the analyzer. 

The metal-metal interaction and conductivity increase with pressure using bulkier ammines increases the Pt-Pt distance. Although palladium-containing ions can be substituted for the platinum species, the optical properties and metal-metal interaction causing pronounced dichroism are... 

That magnetic measurements often raise more problems than they solve, is demonstrated for the indicated compound. We prepared a series of [ (C2H5N] i,An(NSC) e compounds (An = Th, U, Np, Pu) with cubic coordination of the actinide ion. We derived a consistent interpretation of the magnetic and optical properties of the uranium and the neptunium compounds (6 ). In the case of Pu we expect an isolated T1 ground state and a first excited state at about 728 cm-1. To our surprise we found a magnetic ground state much more pronounced than in the case of the hexachloro-complex, Fig. 4. 

Bimetallic nanoparticles, either as alloys or as core-shell structures, exhibit unique electronic, optical and catalytic properties compared to pure metallic nanopartides [24]. Cu-Ag alloy nanoparticles were obtained through the simultaneous reduction of copper and silver ions again in aqueous starch matrix. The optical properties of these alloy nanopartides vary with their composition, which is seen from the digital photographs in Fig. 8. The formation of alloy was confirmed by single SP maxima which varied depending on the composition of the alloy. 

The synthesis of bimetallic nanoparticles is mainly divided into two methods, i.e., chemical and physical method, or bottom-up and top-down method. The chemical method involves (1) simultaneous or co-reduction, (2) successive or two-stepped reduction of two kinds of metal ions, and (3) self-organization of bimetallic nanoparticle by physically mixing two kinds of already-prepared monometallic nanoparticles with or without after-treatments. Bimetallic nanoparticle alloys are prepared usually by the simultaneous reduction while bimetallic nanoparticles with core/shell structures are prepared usually by the successive reduction. In the preparation of bimetallic nanoparticles, one of the most interesting aspects is a core/shell structure. The surface element plays an important role in the functions of metal nanoparticles like catal5dic and optical properties, but these properties can be tuned by addition of the second element which may be located on the surface or in the center of the particles adjacent to the surface element. So, we would like to use following marks to inscribe the bimetallic nanoparticles composed of metal 1, Mi and metal 2, M2. 

An example of this process of data analysis is provided by the work of Yubero et al. (2000), who studied the structure of iron oxide thin films prepared at room temperature by ion beam induced chemical vapour deposition. Such films find important applications because of their optical, magnetic, or magneto-optical properties. They were produced by bombardment of a substrate with Oj or Oj + Ar+ mixtures, and Figure 4.15 shows RBS spectra of two iron oxide thin films prepared on a Si substrate by each of these bombardment methods. 

A Ca2+-ion selective rigid -flexible - rigid type bichromophoric sensors based on the conformation liable bis-squaraine dyes 27 works on the principle of Cation-steered folding, which leads to dramatic perturbations in the optical properties as a result of exciton interactions [87],... 

Hydrophilic polymers (Table 5) provide a matrix which is comparable to an aqueous environment. Ions can diffuse quite freely, but the possible water uptake (10-1000%) can cause significant swelling of the polymer. Swelling of the matrix affects the optical properties of the sensors and, consequently, the signal changes. Immobilization of the indicator chemistry usually is achieved via covalent bonding to the polymer. 

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