Capacity semiconducting

Ceria is another type of mixed conducting oxide which has been shown already to induce electrochemical promotion.71 Ceria is a catalyst support of increasing technological importance.73 Due to its nonstoichiometry and significant oxygen storage capacity it is also often used as a promoting additive on other supports (e.g. y-A Cb) in automobile exhaust catalysts.79 It is a fluorite type oxide with predominant n-type semiconductivity. The contribution of its ionic conductivity has been estimated to be 1-3% at 350°C.71... 

The semiconducting properties of the compounds of the SbSI type (see Table XXVIII) were predicted by Mooser and Pearson in 1958 228). They were first confirmed for SbSI, for which photoconductivity was found in 1960 243). The breakthrough was the observation of fer-roelectricity in this material 117) and other SbSI type compounds 244 see Table XXIX), in addition to phase transitions 184), nonlinear optical behavior 156), piezoelectric behavior 44), and electromechanical 183) and other properties. These photoconductors exhibit abnormally large temperature-coefficients for their band gaps they are strongly piezoelectric. Some are ferroelectric (see Table XXIX). They have anomalous electrooptic and optomechanical properties, namely, elongation or contraction under illumination. As already mentioned, these fields cannot be treated in any detail in this review for those interested in ferroelectricity, review articles 224, 352) are mentioned. The heat capacity of SbSI has been measured from - 180 to -l- 40°C and, from these data, the excess entropy of the ferro-paraelectric transition... 

The most unusual and interesting feature of these polymers is their capacity to switch between insulating and conducting (or semiconducting) states. All other materials, with the only additional exception of some intercalation compounds, are normally found only as conductors or semiconductors or insulators, without the facility to switch between these states. 

A certain relationship, which exists between the bulk and surface properties of semiconducting materials and their electrochemical behavior, enables, in principle, electrochemical measurements to be used to characterize these materials. Since 1960, when Dewald was the first to determine the donor concentration in a zinc oxide electrode using Mott-Schottky plots, differential capacity measurements have frequently been used for this purpose in several materials. If possible sources of errors that were discussed in Section III.3 are taken into account correctly, the capacity method enables one to determine the distribution of the doping impurity concentration over the surface" and, in combination with the layer-by-layer etching method, also into the specimen depth. The impurity concentration profile can be constructed by this method. It has recently been developed in greatest detail as applied to gallium arsenide crystals and multilayer structures. 

Figure 1. Raman spectra in the radial breathing mode region for a) a Nd YAG-produced sample with a H2 adsorption capacity of 7 wt%, and b) a sample produced with the Alexandrite laser operating with a 200 ns pulse width at a peak power of 10.5 MW/cm. The red curves (highest curve on each figure) are for Raman excitation at 632.8 nm and show the SWNT size distribution for excited metallic and semiconducting tubes. The blue curves (lowest curve on each figure) were obtained at 488 nm and show predominantly semiconducting tubes.

Fig. 7 Double logarithmic plot of film capacity C versus film thickness d. Al as example of an insulating, homogeneous film [21]. Fe as example of a semiconducting film with capacities depending on d and U (Schottky-Mott). Au as example of an insulating thin film with a porous hydrated film outside. NiOOH on Au as example of a conducting deposition film [23].

Leifer et al. [105]. used Li MAS NMR to study the strucmre of lithiated silver vanadium oxide, Liy4g2V40n, where x = 0.72,2.13, and 5.59. This compound is used in biomedical applications as a primary battery, particularly as the power source for implantable cardiac defibrillators (ICDs). Silver vanadium oxide is a vanadium bronze with semiconducting properties. It has been used successfully as a cathode material in the battery of ICDs due to its high rate capability and its high theoretical capacity (315 mAh/g) to 2 V. Electrochemical and structural studies of the average structure were performed by various authors who concluded that the systems undergoes a multistep reduction mechanism and forms silver metal in the early stage of the overall reaction [106-108]. 

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