Extraordinary Dielectric Properties at Heterojunctions of Amorphous Ferroelectrics
Extraordinary Dielectric Properties at Heterojunctions of Amorphous Ferroelectrics
复制标题
DOI：
10.1021/jacs.8b09603
复制
发表时间：
2018-12-26
影响因子：
15
通讯作者：
Goodenough, John B.
中科院分区：
文献类型：
--
作者：
Braga, M. Helena;Oliveira, Joana E.;Goodenough, John B.
从晶体管到电容器的各种电气应用都需要具有高介电常数的材料。由两种不同类型的测量和不同的一致性分析表明，组成为A(2.99)Ba(0.005)ClO(A=Li，Na)的铁电非晶氧化物(玻璃)碱离子电解质具有极高的介电常数，如果玻璃条件适当，介电常数从25℃时的10(9)到220℃时的10(10)。在25℃时，这些异常高的介电性能与相当于锂离子电池最佳有机-液体电解液的碱离子电导率共存，并且Au/玻璃电解液/Au电池的循环伏安(CV)在-10~+10V范围内稳定。微观上解释CV曲线所有关键特征的模型表明，在施加电压V=+//-2.1V时，Au/玻璃电解液/Au异质结中金/电解液界面处形成的双电层电容反转极化，导致单个物理电容器在-10~+10V之间产生几乎相等的三个放电电容。
Materials having a high dielectric constant are needed for a variety of electrical applications from transistors to capacitors. Ferroelectric amorphous-oxide (glass) alkali-ion electrolytes of composition A(2.99)Ba(0.005)ClO (A = Li, Na) are shown by two different types of measurement and different consistent analyses to have extraordinarily high dielectric constants, varying from 10(9) at 25 degrees C to 10(10) at 220 degrees C if the glass is properly conditioned. These anomalously high dielectric properties coexist with alkali-ion conductivities at 25 degrees C that are equivalent to those of the best organic-liquid electrolytes of a Li-ion cell, and cyclic voltammetry (CV) in a Au/glass electrolyte/Au cell is stable from -10 to +10 V. A model to interpret microscopically all the key features of the CV curves shows that the electric-double-layer capacitors that form at the gold/electrolyte interfaces in the Au/glass electrolyte/Au heterojunction reverse polarization at an applied voltage V = +/- 2.1 V, resulting in three almost equivalent discharging capacitances for a single physical capacitor from -10 to +10 V.