电介质
陶瓷
铁电性
掺杂剂
电热效应
材料科学
铁电陶瓷
压电
相界
电场
相(物质)
正交晶系
空间电荷
相变
分析化学(期刊)
凝聚态物理
复合材料
兴奋剂
光电子学
晶体结构
化学
结晶学
物理
电子
量子力学
有机化学
色谱法
作者
Xiangjian Wang,Xiaojie Lou,Wenping Geng,Yingbang Yao,Tao Tao,Bo Liang,Sheng‐Guo Lu
摘要
The 0.95K0.42Na0.58Nb0.96Sb0.04O3–0.02BaZrO3–0.03Bi0.5K0.5HfO3 ceramic was fabricated via a conventional solid-state reaction. This ceramic exhibits the diffuse polymorphic phase boundary (PPB) near room temperature. The dielectric, ferroelectric, electromechanical, electrocaloric, and dielectric energy storage properties were studied systemically. The normalized large signal d33* values are approximately 400–600 pm/V at measured temperatures and electric fields, which are larger than or comparable with the values reported in other lead-free compositions. The electrocaloric strength is enhanced at the broad region of PPB provided by the indirect and direct measurements. At low field of 30 kV/cm, the dielectric energy storage is ∼0.12–018 J/cm3 at relative broad temperature range due to the diffuse nature of polymorphic phase boundary. Theoretical simulations reveal that multi-element dopants, such as Sb5+, Hf4+, Zr4+, and Bi3+ ions, could induce the breaking of local structure symmetry in the orthorhombic phase to form the PPB. In addition, the charge distribution may also break the long-range ferroelectric order through the analysis of Bader charge. Our study suggests that the K0.5Na0.5NbO3-based ceramic exhibits improved performance and good thermal stability in piezoelectric, electrocaloric, and dielectric energy storage characteristics in terms of the design of multi-element dopants to form the PPB and it will benefit the promising applications in electronic devices.
科研通智能强力驱动
Strongly Powered by AbleSci AI