Microstructural and dielectric properties of hot-pressed organic composite: benzil-4-aminobenzophenone

Transparent binary organic composites of nonlinear optical (NLO) materials (benzil--4-aminobenzophenone) were prepared by a hot-pressing technique. The microstructural characterization by scanning electron microscope revealed an increase in grain size with increasing hot-pressing conditions. The dielectric studies as a function of frequency (1 kHZ to 10 MHz) show a decrease in dielectric constant with increase in frequency, while it increases with increasing temperature at lower frequencies. The X-ray diffraction studies and infrared spectroscopy confirm the true nature of the composite. An attempt was made to predict the dielectric constants of the present organic composite using Reynolds and Hough as well as Maxwell's equations of dielectric mixture formulae. The theoretically obtained values of the dielectric constants are found to be slightly higher than that of experimental values. The discrepancy in these values is attributed to the non-spherical nature of the crystallites in the composite. © 2001 Kluwer Academic Publishers