Colossal permittivity in (In_1/2Nb_1/2)_xTi_1−xO₂ ceramics prepared by a glycine nitrate process

详细信息    查看全文

• 作者：Theeranuch Nachaithong^a ; ^b ; Prasit Thongbai^b ; ^c ; ^{pthongbai@kku.ac.th" class="auth_mail" title="E-mail the corresponding author} ; ^{tprasit259@gmail.com" class="auth_mail" title="E-mail the corresponding author} ; Santi Maensiri^d
• 关键词：Surface barrier layer capacitor (SBLC) ; TiO2 ; Colossal permittivity ; Loss tangent ; Impedance spectroscopy
• 刊名：Journal of the European Ceramic Society
• 出版年：2017
• 出版时间：February 2017
• 年：2017
• 卷：37
• 期：2
• 页码：655-660
• 全文大小：1568 K

文摘

(In + Nb) co-doped TiO₂ nanoparticles with very low dopant concentrations were prepared using a glycine nitrate process. A pure rutile—TiO₂ phase with a dense microstructure and homogeneous dispersion of dopants was achieved. By doping TiO₂ with 1.5% (In + Nb) ions, a very high dielectric permittivity of ε′ = 42,376 and low loss tangents of tanδ = 0.06 (at room temperature) were achieved. The large conduction activation energy at the grain boundary decreased with decreasing dopant concentration. The colossal permittivity was primarily attributed to the internal barrier layer capacitor (IBLC) effect. The dominant effect of interfacial polarization at the non–Ohmic sample–electrode contact was observed when the dopant concentration was ≤1.0 mol%. Interestingly, the sample–electrode contact and resistive–outer surface layer effects, i.e., surface barrier layer capacitor (SBLC) effect, has also an effect on the colossal dielectric response in (In + Nb) co-doped TiO₂ ceramics.