Doping homogeneous

Frant and Ross [15] invented an ion-elective fluoride-type electrode. Its measuring membrane was made of europium-doped homogeneous lanthanum fluoride crystal membrane. Measuring fluoride ion concentration is not an easy task on the other hand, the contradiction concerning the beneficial and the toxic physiological effects of fluorine ion intake created intensive debates. Therefore, the electrode that made the simple potential measuring technique applicable for fluoride measurements became very popular in practice. 

It was found that that in the case of soft beta and X-ray radiation the IPs behave as an ideal gas counter with the 100% absorption efficiency if they are exposed in the middle of exposure range ( 10 to 10 photons/ pixel area) and that the relative uncertainty in measured intensity is determined primarily by the quantum fluctuations of the incident radiation (1). The thermal neutron absorption efficiency of the present available Gd doped IP-Neutron Detectors (IP-NDs) was found to be 53% and 69%, depending on the thicknes of the doped phosphor layer ( 85pm and 135 pm respectively). No substantial deviation in the IP response with the spatial variation over the surface of the IP was found, when irradiated by the homogeneous field of X-rays or neutrons and deviations were dominated by the incident radiation statistics (1). 

References to a number of other kinetic studies of the decomposition of Ni(HC02)2 have been given [375]. Erofe evet al. [1026] observed that doping altered the rate of reaction of this solid and, from conductivity data, concluded that the initial step involves electron transfer (HCOO- - HCOO +e-). Fox et al. [118], using particles of homogeneous size, showed that both the reaction rate and the shape of a time curves were sensitive to the mean particle diameter. However, since the reported measurements refer to reactions at different temperatures, it is at least possible that some part of the effects described could be temperature effects. Decomposition of nickel formate in oxygen [60] yielded NiO and C02 only the shapes of the a—time curves were comparable in some respects with those for reaction in vacuum and E = 160 15 kJ mole-1. Criado et al. [1031] used the Prout—Tompkins equation [eqn. (9)] in a non-isothermal kinetic analysis of nickel formate decomposition and obtained E = 100 4 kJ mole-1. 

Figure 5. Two- and three-dimensional representations of relative luminescence flux of uranyl ion-doped glass beads, measured in a 100 X 100 raster with 10,000 data points. Depicted are a homogeneously doped bead (a) and a nonhomogeneously doped bead (b).

The sol-gel technique was also used to prepare solid electrolytes containing MEEP, triethoxysilane (TEOS) and lithium triflate. Homogeneous, transparent and mechanicaUy stable materials have been obtained by Gughelmi [611] from a partially hydroxylated MEEP and TEOS, which after doping with LiSOjCFj exhibited a conductivity in the range 3x10 S cm at 60 °C. 

Couto et al. [11] developed a flow injection system with potentiometric detection for determination of TC, OTC, and CTC in pharmaceutical products. A homogeneous crystalline CuS/Ag2S double membrane tubular electrode was used to monitor the Cu(II) decrease due to its complexation with OTC. The system allows OTC determination within a 49.1 1.9 x 103 ppm and a precision better than 0.4%. A flow injection method for the assay of OTC, TC, and CTC in pharmaceutical formulations was also developed by Wangfuengkanagul et al. [12] using electrochemical detection at anodized boron-doped diamond thin-film electrode. The detection limit was found to be 10 nM (signal-to-noise ratio = 3). 

An important point concerning the spectra in Figure 3.71 is that at intermediate doping levels three principal absorption bands can be seen, at c. l.OeV, 2.7eV and 3.6eV, that are not simply the superposition of the as-grown and neutral polymer absorptions. The authors interpreted this observation in terms of the homogeneous doping of the film throughout its bulk, not just the oxidation of the surface layer or the layer next to the electrode. 

There are a number of ways to introduce dopants into an EC-ALE deposit. For instance, they can be introduced homogeneously throughout the deposit, or delta doped into the structure. For a relatively homogeneous distribution, low concentrations of oxidized precursors can be incorporated into the reactant solutions. By using very low concentrations, the amounts incorporated in each atomic layer will be limited. The dopant can also be incorporated in its own cycle step. Again, a low concentration would be used so that some fraction of an atomic layer is introduced each cycle. Alternatively, a delta doping scheme can be constructed where a fraction of an atomic layer of dopant is deposited every set number of cycles. All these scenarios involve only a simple modification of the EC-ALE program. 

The doping is homogeneous over the crystal, whereas melt doped Ge sensors show dispersive properties even when they are cut from nearby volumes of the same chip ... 

To eliminate the above uncertainties in the interpretation of the transport data, Hall-effect measurements were combined with layer removal on homogeneously doped n-type layers (Johnson and Herring, 1988a). The... 

Etch rate and homogeneity and anisotropic characteristics are the predominant factors in determining the resulting micro system device properties. Temperature and concentration of the KOH solution as well as the doping concentration of the silicon material have the largest impact on these properties and have to be thoroughly controlled. 

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