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

✍ Scribed by A. Aoujgal; H. Ahamdane; M.P.F. Graça; L.C. Costa; A. Tachafine; J.C. Carru; A. Outzourhit

• Book ID: 104093790
• Publisher: Elsevier Science
• Year: 2010
• Tongue: English
• Weight: 625 KB
• Volume: 150
• Category: Article
• ISSN: 0038-1098
• DOI: 10.1016/j.ssc.2010.03.035

✦ Synopsis

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 VF = 122 K. The results are discussed in terms of existing models.