Excellent Capacitor-Varistor Properties in Lead-Free CaCu3Ti4O12-SrTiO3 System with a Wrinkle Structure via Interface Engineering

被引：65

作者：

Mao, Pu ^{[1
,2
]}

Wang, Jiping ^{[1
]}

He, Liqiang ^{[1
]}

Zhang, Lixue ^{[1
]}

Annadi, Anil ^{[3
]}

Kang, Fang ^{[1
]}

Sun, Qinzhao ^{[1
]}

Wang, Zepeng ^{[1
]}

Gong, Hao ^{[2
]}

机构：

[1] Xi An Jiao Tong Univ, Sch Mat Sci & Engn, State Key Lab Mech Behav Mat, Xian 710049, Peoples R China

[2] Natl Univ Singapore, Dept Mat Sci & Engn, Singapore 117576, Singapore

[3] Vellore Inst Technol, Sch Adv Sci, Dept Phys, Vellore 632014, Tamil Nadu, India

来源：

ACS APPLIED MATERIALS & INTERFACES | 2020年 / 12卷 / 43期

基金：

中国国家自然科学基金;

关键词：

lead-free giant dielectrics; CaCu3Ti4O12; ceramics; interface structure; dielectric properties; nonlinear behaviors; dual-function; PERFORMANCE COLOSSAL PERMITTIVITY; GIANT DIELECTRIC RESPONSE; ENHANCED BREAKDOWN FIELD; PINNED DEFECT-DIPOLES; ELECTRICAL-PROPERTIES; NONOHMIC PROPERTIES; SINTERING TEMPERATURE; GRAIN-BOUNDARY; SOL-GEL; CERAMICS;

D O I：

10.1021/acsami.0c13067

中图分类号：

TB3 [工程材料学];

学科分类号：

0805 ; 080502 ;

摘要：

Lead-free perovskite CaCu3Ti4O12 (CCTO) dielectrics are extremely important candidates for capacitor-varistor dual-function materials. However, their overall success in applications is somewhat controlled by the longstanding issues such as relatively large dielectric loss and insufficiently high electric breakdown field. Herein, we report the success in the preparation of an optimized lead-free (1-x)CaCu3Ti4O12-xSrTiO(3) (CCTO-STO) composite system with improved dielectric and nonlinear properties via interface engineering. Interestingly, looking closer at the grain boundaries using transmission electron microscopy, it is found that an obvious interface region with a transition layer of a wrinkled structure is formed between the CCTO matrix phase and STO dopant phase. Significantly, all the composite ceramic samples present high permittivity in the order of about 10(3) to 10(4), and the 0.9CCTO-0.1STO composite ceramic sample exhibits a lower dielectric loss of about 0.068 at room temperature and at 1 kHz. Excitingly, the optimized 0.9CCTO-0.1STO composite ceramic sample also exhibits a remarkably elevated breakdown field strength of about 14.03 kV/cm and a large nonlinear coefficient of about 16.11. The improvement in nonlinear properties with a high breakdown field strength and large nonlinear coefficient could be attributed to the interfacial effect in the composite structure, originating from the formation of the transition layer with a wrinkle structure at the interface between CCTO and STO phases. Such effects can result in great electrical heterogeneity caused by the higher resistance of the grain boundary and the enhanced potential barrier at the interface region. The new insights on the formation of the interfacial wrinkle structure near the phase boundaries of the CCTO-STO composite system and their effects on improvement of electrical properties can stimulate future research on lead-free CCTO-STO-based systems toward capacitor-varistor dual-function applications and may offer an effective way to design other lead-free dielectric materials as well.

引用

页码：48781 / 48793

页数：13

共 58 条

[1] Characterization of grain boundary impedances in fine- and coarse-grained CaCu3Ti4O12 ceramics -: art. no. 094124 [J].