Orientational defects activation energies

At elevated temperatures, where the electron lifetime was much shorter than the pulse lengths of a few nanoseconds used, a second mobile species could be observed as a slowly decaying after-pulse conductivity component for large pulses. This was attributed to proton conduction with a proton mobility of 6.4 x 10 cm /Vs in H,0 ice and a somewhat lower value in D2O ice. ° In the case of the proton, the mobility was found to have an apreciable negative activation energy of 0.22 eV. The motion and trapping of protons was tentatively explained in terms of an equilibrium between free protons and a proton complexed with an orientational L-defect. °... 

The situation is quite similar to that of ice. A dielectric measurement on a KOH-doped THE showed that the relaxation time t for the reorientational motion was dramatically shortened by the dopant, possibly by creating a pair of the orientational defects proposed by Bjemim. Not only the absolute value of t but also the activation energy for the process decreased by the dopant, as shown in Fig. 3. The value of x at 70 K is 10- times smaller than that for pure (undoped) sample. This is the reason why the ordering transition has escaped from observation for a pure sample by a kinetic reason appeared now at 62 K in the doped sample by a catalytic action of the dopant within a reasonable time. Also given in the figure is a Cole-Cole plot of the dielectric permittivity of the KOH-doped THF hydrate. The distribution of dielectric relaxation times is much wider in the doped sample than in the pure sample. 

Consequently, dopant concentration, crystal orientation, and defects play an imporant role in the etching process. Addition of a diluent results in an activation energy that is between these two ranges. 

The thermodynamic activity of adsorbed H atoms depends not only on their total concentration but also on the invidual properties of the electrode surface, its local crystallographic orientation, its morphology and the presence and concentration of defects in the lattice structure. All these effects influence the activation energies of... 

The aforementioned measurement proved that the system reliability had been compromised, requiring action to be taken, such as the execution of new studies on energy consumption by the W SN, in order to ascertain if some of the defect sensors could be recovered. If this action failed to yield the desired effect, a localized investigation of the defective sensors would be necessary, when they could be repaired or even replaced. Considering that is possible to take advantage of WSN in terms of reductions of eneigy, if compared with another centralized solutions, these benefits just only is possible if the data quality is reliable. For this purpose, is necessary to establish a set of dimension oriented to the specific issue. For example, the computation of completeness dimension should be more than 95%, that means, 95% of sensors should be active. 

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