Correlation between phase compatibility and efficient energy conversion in Zr-doped Barium Titanate
Correlation between phase compatibility and efficient energy conversion in Zr-doped Barium Titanate
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DOI：
10.1038/s41598-020-60335-5
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发表时间：
2020-02
影响因子：
4.6
通讯作者：
M. Wegner;H. Gu;R. James;E. Quandt
中科院分区：
文献类型：
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作者：
M. Wegner;H. Gu;R. James;E. Quandt
最近基于一阶铁电相变的热电能量转换装置和电热装置的演示表明，降低铁电相变的滞后和循环可逆性是这项技术进步的标准。这些论证和最近对氧化物相变滞后的研究表明，满足超相容条件可以有效地降低滞后，但对于只有少数低对称相变体的系统来说是有限的。特别是，人们普遍认为，在经典的立方到四方相变中，只有三个四方变体只有六个孪晶系统，为了改善晶体兼容性而进行的调谐将具有有限的价值。这项工作表明，相反，为了改善晶体结构的兼容性，即使在低掺杂水平下，通过调整Ba(Ti1-xZrx)O_3中的晶格参数，也能显著改善相变性能和铁电能量转换性能，即使在低掺杂水平下也是如此。具体来说，相变滞后降低了25%，相变时的极化/温度比dp/dt的最大值提高了10%。
Recent demonstrations of both heat-to-electricity energy conversion devices and electrocaloric devices based on first-order ferroelectric phase transformations identify the lowering of hysteresis and cyclic reversibility of the transformation as enabling criteria for the advancement of this technology. These demonstrations, and recent studies of the hysteresis of phase transformations in oxides, show that satisfying conditions of supercompatibility can be useful for lowering hysteresis, but with limitations for systems with only a few variants of the lower symmetry phase. In particular, it is widely accepted that in a classic cubic-to-tetragonal phase transformation, with only three tetragonal variants having only six twin systems, tuning for improved crystallographic compatibility will be of limited value. This work shows that, on the contrary, the tuning of lattice parameters in Ba(Ti1-xZrx)O3for improved crystallographic compatibility, even at low doping levels of Zr (x ≤ 0.027), give significant improvement of transformation and ferroelectric energy conversion properties. Specifically, the transformation hysteresis is lowered by 25%, and the maximum value of the polarization/temperature ratio dP/dT at the phase transformation is increased by 10%.