The problem of phase transitions in PZT based solid solutions, Pb(Mg1/3Nb2/3)O3, Pb(In1/2Nb1/2)O3 and "relaxor ferroelectricity." -: 1.: Experimental results and phase diagrams for PZT based solid solutions

In the present paper the phenomena predicted in [1] for substances with coexisting FE and AFE phases coexistence is experimentally shown. The examples of PZT-based solid solutions are investigated. The solid solutions for which FE and AFE states have equal or close energy stability possess the following experimental properties: - a high degree of (paraelectric) PE phase transition diffuseness; - an essential dispersion of permittivity in the region of diffuse maximum of the dependences epsilon'(T) and epsilon''(T) and fulfilment of the Fogel-Fulcher law; - an increase of the measuring AC field amplitude E-0 leads to a linear decrease of T' m and to an increase of epsilon'(T' m ); the tangent of T' m (E-0) dependence decreases with an increase of AC field frequency; - the presence of effects which point to the existence of polar phase domains at temperatures essentially higher than T' m and T'' m ; - dependence of their properties on the sample's history; - a long-duration relaxation.