Matrix Active Micro- and Nanocomposites Based on the Polymer, Semiconductive and Ferropiezoceramic Materials

Abstract

Active composite materials are a wide class of material used in radio engineering, electronics, optoelectronics, pyroand piezotechnic. The possibility of application of created electrets, piezoand pyroelectrics, posistors, piezoresistors, varistors, photoresistors, photovoltaic elements and photoelectrets based on the active composites is multiform beginning from various acoustoelectric transducers, acoustic generators, sensors of heat flow, image transducers, photoelements of information recording and storing, until using for radiation protection of spaceships, revealing of underwater objects, seismic and geophysics exploration, also for solving many problems of creating of alternative energy sources (for example, photovoltaic) and medical-biological problems. At present, there are mainly four directions in area of creating abovementioned elements based on the solid dielectrics and semiconductors. First of them is connected with creating new ferropiezoelectric and semiconductive materials mainly based on the barium titanate, plumbum-zirconium-titanate (PZT), АIIВVI, АIIIВV, АIIIВVI, АIVВVI, also semiconductors doped by rare-earth elements. Second direction is based on the synthesis of new polymer dielectrics revealing electret, piezo-, pyroelectric and photoelectric properties. Third direction is connected with creating various composite materials based on the polymer (matrix) dispersed by inorganic ferropiezoelectric or semiconductive fillers. Forth direction discovers new possibilities connected with creation various nanocomposite active materials including hybrid materials consisting of matrix nanoand micropiezoelectric composites. The establishment of interconnection between characteristics of composite materials and properties of polymer, inorganic, ferroelectric and semiconductive phases is a key task on the way of solving of the very important problem of creating microand nanoelectric material. Numerous investigations of ferroand piezoelectric materials have shown that the usage multicomponent piezomaterials based on PZT as inorganic phase is most perspective for obtaining high effective pyro-, piezoelectrics and electrics. It should be noted that at present by variation of composition and number of components in PZT family it is impossible further to improve properties of piezo-, pyroelectric and electret materials. It is caused by that, the increase of piezoand pyroelectric coefficients due to regulation (increase) of ferrosoftness and electromechanical characteristics is directly accompanied by a decreasing of pyroand piezoelectric responses owing to increase of