Structural and relaxor behavior of ceramics obtained by a solid-state reaction

Ba [ Zr x Ti 1 − x − y ] ( Zn 1 / 3 Nb 2 / 3 ) y O 3 (BZT–ZN) ceramics ( x = 0.1 ) were prepared by the solid-state reaction route and their structural and dielectric properties were investigated. It was found at room temperature that the ceramics with y = 0 , 0.05 and 0.1 present perovskite-type cubic structure. The temperature and frequency dependence of the dielectric constant was investigated in the temperature range from 80 to 400 K and for frequencies ranging from 0.1 to 500 kHz. It was observed that when y increases from 0 to 0.1, the transition temperature decreases and the degree of diffuseness of the phase transition increases. For y = 0.1 , a clear relaxor behavior was noted. In this case, the dielectric relaxation rate followed de Vogel–Fulcher relation with an activation energy of E a = 0.1 eV , an attempt frequency F 0 = 2 × 10 14 Hz and a static freezing temperature T V F = 122 K . The results are discussed in terms of existing models.