Dielectric measurements, pore size effect

Dynamic Monte Carlo Simulation and Dielectric Measurements of the Effect of Pore Size on Glass Transition Temperature and tiie State of the Glass... 

Far-IR reflectivity spectra of the (Pbo 5Cao 5)(Eeo 5Tao 5)03 specimens sintered at 1250°C for 30 min were taken to calculate the intrinsic dielectric loss at microwave frequencies. The spectra of the specimens were fitted by 10 resonant modes. The calculated reflectivity spectra are well fitted with the measured ones, as shown in Figure 22.4 and Table 22.2. The dispersion parameters of the specimens in Table 22.2 were determined by the Kramers-Kronig analysis and the classical oscillator model. The calculated values were higher than the measured ones by Hakki and Coleman s method, which is due to extrinsic effects such as grain size and porosity. Assuming the mixture of dielectrics and spherical pore with 3-0 connectivity, the measured loss quality also depends on the porosity as well as the intrinsic loss of materials, and Equation 22.24 may be modified for the loss quality, as in Equation 22.25 ... 

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