THE GIANT DIELECTRIC-CONSTANT OF OPAL CONTAINING SODIUM-NITRATE NANOPARTICLES

The temperature dependence of the die!ectric constant of opal containi ng dispersed sodium nitrate (o-NaNO2) was measured in the temperature interval from 370 to 600 K. Features associated with the ferroelectric and melting-freezing phase transitions in sodium nitrite particles we re observed. A low-temperature shift (similar to 10 K) of the Curie po int of o-NaNO2 compared to that of the bulk NaNO2 was found on cooling , and significant broadening (up to similar to 100 K) of the melting-f reezing phase transition was observed. A giant enhancement of the diel ectric constant (up to similar to 10(8) at 100 Hz) of o-NaNO2 was foun d at high temperatures, when the sodium nitrite particles melt, transf orming to electrolytic drops.