TY - JOUR
T1 - The role of Co in the BaTiO3-Na0.5Bi0.5TiO3 based X9R ceramics
AU - Sun, Yue
AU - Liu, Hanxing
AU - Hao, Hua
AU - Zhang, Lin
AU - Zhang, Shujun
N1 - Funding Information:
This work was supported by the Key program of National Natural Science Foundation of China (No. 50932004 ), International Science and Technology Cooperation Program of China ( 2011DFA52680 ), National Natural Science Foundation of China (Nos. 51372191 , and 51102189 ), the program for New Century Excellent Talents in University (No. NCET-11-0685 ), and the Fundamental Research Funds for the Central Universities ( WUT:2014-IV-134 ).
Publisher Copyright:
© 2014 Elsevier Ltd and Techna Group S.r.l. All rights reserved.
PY - 2015
Y1 - 2015
N2 - Ceramics in BaTiO3-Na0.5Bi0.5TiO3-Nb2O5-Co3O4 (BT-NBT-Nb-Co) system were fabricated to satisfy the EIA-X9R specification (-55 ∼ 200 °C, ΔC/C ≤ ± 15%) of multilayer ceramic capacitors. The role of Co in this system was investigated. The core-shell structure was found to exist in the system, as confirmed by transmission electron microscopy (TEM), accounting for the high dielectric temperature stability. The Co can regulate the reaction between Nb and BT-NBT to adjust the core-shell structure, where the optimum dielectric properties were achieved at Nb/Co = 3, with dielectric constant being 930 at room temperature and capacitance variation being less than 15% in the temperature range from - 55 °C to 200 °C. The impedance spectroscopy was fitted by 3RC equivalent circuit, corresponding to the grain, grain boundary and ceramic/electrode interface region for the Co modified BT-NBT system. The conduction activation energy of grain was found to decrease with increasing Co concentration, where the conduction mechanism of grain and grain boundary are both sensitive to the Co concentration.
AB - Ceramics in BaTiO3-Na0.5Bi0.5TiO3-Nb2O5-Co3O4 (BT-NBT-Nb-Co) system were fabricated to satisfy the EIA-X9R specification (-55 ∼ 200 °C, ΔC/C ≤ ± 15%) of multilayer ceramic capacitors. The role of Co in this system was investigated. The core-shell structure was found to exist in the system, as confirmed by transmission electron microscopy (TEM), accounting for the high dielectric temperature stability. The Co can regulate the reaction between Nb and BT-NBT to adjust the core-shell structure, where the optimum dielectric properties were achieved at Nb/Co = 3, with dielectric constant being 930 at room temperature and capacitance variation being less than 15% in the temperature range from - 55 °C to 200 °C. The impedance spectroscopy was fitted by 3RC equivalent circuit, corresponding to the grain, grain boundary and ceramic/electrode interface region for the Co modified BT-NBT system. The conduction activation energy of grain was found to decrease with increasing Co concentration, where the conduction mechanism of grain and grain boundary are both sensitive to the Co concentration.
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U2 - 10.1016/j.ceramint.2014.08.140
DO - 10.1016/j.ceramint.2014.08.140
M3 - Article
AN - SCOPUS:84923062558
SN - 0272-8842
VL - 41
SP - 931
EP - 939
JO - Ceramics International
JF - Ceramics International
IS - 1
ER -