Structural and relaxor behavior in lead-free (Ba_0.8Sr_0.2)Ti_{1∿span style='font-style: italic'>x}(Zn_1/3Nb_2/3)_xO₃ ceramics

详细信息    查看全文

• 作者：Nabil Dhifallah^a ; Olfa Turki^a ; Mimoun El Marssi^b ; Mohamed Dammak^c ; Hamadi Khemakhem^a ; ^{khemakhemh@yahoo.fr" class="auth_mail" title="E-mail the corresponding author}
• 关键词：Perovskite structure ; Phase transition ; Relaxor behavior
• 刊名：Ceramics International
• 出版年：2016
• 出版时间：1 May 2016
• 年：2016
• 卷：42
• 期：6
• 页码：6657-6663
• 全文大小：2616 K

文摘

The Solid solutions of (1−x)Ba_0.8Sr_0.2TiO₃−xBa(Zn_1/3Nb_2/3)O₃ (BST–BZN) with 0.025≤x≤0.15 were prepared by a high temperature solid-state reaction technique. The effects of the Ba(Zn_1/3Nb_2/3)O₃ addition on the phase composition in the B site on structural and dielectric properties was investigated. The room temperature X-ray diffraction analyses of all ceramics revealed a perovskite phase with a composition dependent symmetry. The temperature and frequency dependence of the dielectric permittivity and losses have been explored. While ceramics of compositions x≤0.05 showed normal ferroelectric behavior, while ceramics with x≥0.1 were of relaxor type. It was found that degree of diffuseness and the relaxor effect increased, whereas the transition temperature (T_C or T_m) decreased when both zinc and niobium were introduced in the Ba_0.8Sr_0.2TiO₃ lattice. For the composition with x≥0.1, the frequency depend on T_m, satisfying the Vogel–Fulcher formula, which indicates a relaxor bahavior.