THE EFFECT OF TELLURIUM VAPOR ON THE STRUCTURE FORMATION AND DIELECTRIC PROPERTIES OF A MULTICOMPONENT SYSTEM BASED ON SODIUM-POTASSIUM NIOBATE

The paper presents the results of studying the effect of paratellurite vapor during sintering on the dielectric properties of a multicomponent system based on sodium-potassium niobate ceramics (mKNN) with the general formula (Na0,5K0,49Li0,05Sr0,05)(Nb0,9Ta0,05Ti0,05)O-3. The inclusion of paratellurite in mKNN ceramics changes the shape and increases the grain size by an order of magnitude. Thus, if grains containing only mKNN material have a cubic shape, then the presence of tellurium leads to the formation of grains in the form of sufficiently long tubes (when the length is several times greater than the diameter) with a porous internal structure. The addition of TeO2 to the mKNN composition leads to the disappearance of the maximum observed for mKNN on the temperature dependence of the permittivity in the region of 220-250 degrees C, which corresponds to a nonferroelectric structural phase transition in KNN ceramics, and to smoothing the resonant-antiresonant peak in the range of 5-15 MHz, which appears in the KNN system with the introduction of modifiers.