Ceramic-based dielectric capacitors are becoming more and more important in electronic devices.The ceramics of 0.93K_(0.5)Na_(0.5)NbO_(3)–0.07Bix(Mg_(1/3)Nb_(2/3))O_(3)(0.93KNN–0.07BixMN)(x?0:60,2/3,0.75 and 0.95)we...Ceramic-based dielectric capacitors are becoming more and more important in electronic devices.The ceramics of 0.93K_(0.5)Na_(0.5)NbO_(3)–0.07Bix(Mg_(1/3)Nb_(2/3))O_(3)(0.93KNN–0.07BixMN)(x?0:60,2/3,0.75 and 0.95)were successfully fabricated by virtue of the solid reaction process in this work.The results showed that the amount of Bi content has a significant impact on the ceramics of 0.93KNN–0.07BixMN.XRD indicates that all specimens exhibit a pure perovskite structure and existing oxygen vacancy in the specimens.The mean grain size for all specimens belong to submicron scale,and the sample of x=0.95 owns the smallest grain size is 0.11m.The maximum dielectric constant increases but the phase transition temperature Tm exhibits a contrary tendency at 1MHz with increasing Bi concentration.Besides,all ceramics are relaxor ferroelectric.The impedance analysis further revealed that the activation energy of the ceramics increases with Bi content.Eventually,the highestηof 58.8%and Wrec of 1.30 J/cm^(3) are simultaneously achieved in the sample with x=0.60.Overall,we demonstrate in this work that stoichiometry control of Bi in 0.93KNN–0.07BixMN ceramics is a practical method to obtain the desired structural,dielectric and energy storage properties.展开更多
基金supported by National Science Foundation of China(Grant Nos.51572163,51577111 and 51607108)the Fundamental Research Funds for the Central Universities(Program Nos.GK201601003,GK201703016,GK201802007,201701011 and 2018CBLZ007).
文摘Ceramic-based dielectric capacitors are becoming more and more important in electronic devices.The ceramics of 0.93K_(0.5)Na_(0.5)NbO_(3)–0.07Bix(Mg_(1/3)Nb_(2/3))O_(3)(0.93KNN–0.07BixMN)(x?0:60,2/3,0.75 and 0.95)were successfully fabricated by virtue of the solid reaction process in this work.The results showed that the amount of Bi content has a significant impact on the ceramics of 0.93KNN–0.07BixMN.XRD indicates that all specimens exhibit a pure perovskite structure and existing oxygen vacancy in the specimens.The mean grain size for all specimens belong to submicron scale,and the sample of x=0.95 owns the smallest grain size is 0.11m.The maximum dielectric constant increases but the phase transition temperature Tm exhibits a contrary tendency at 1MHz with increasing Bi concentration.Besides,all ceramics are relaxor ferroelectric.The impedance analysis further revealed that the activation energy of the ceramics increases with Bi content.Eventually,the highestηof 58.8%and Wrec of 1.30 J/cm^(3) are simultaneously achieved in the sample with x=0.60.Overall,we demonstrate in this work that stoichiometry control of Bi in 0.93KNN–0.07BixMN ceramics is a practical method to obtain the desired structural,dielectric and energy storage properties.
