Li掺杂Ba(Ti1/7Sn1/7Zr1/7Hf1/7Nb1/7Ga1/7Li(1/7-x))O3高熵陶瓷的制备及介电性能研究

近年来，在高熵合金基础上发展起来的高熵陶瓷逐渐引起了研究者的广泛关注，其出现为开发高性能的无机非金属材料提供了新的设计思路。本文采用固相法制备了BaMO3基钙钛矿型高熵陶瓷Ba(Ti1/7Sn1/7Zr1/7Hf1/7Nb1/7Ga1/7Li(1/7-x))O3 (x = 0, 2.3%, 5.3%, 8.3%, 11.3%)，并研究了Li含量对高熵陶瓷物相结构、微观形貌及介电性能的影响。结果表明，Li含量对陶瓷结构的影响不大，陶瓷均保持立方钙钛矿结构，且无杂相产生；陶瓷的晶粒尺寸相对较均匀。当x = 0时，即B位七元等摩尔比Ba(Ti1/7Sn1/7Zr1/7Hf1/7Nb1/7Ga1/7Li1/7)O3高熵陶瓷，其介电常数达到了最大值2920 (@100 Hz)，相较于已报道的不掺Li的六元高熵钙钛矿陶瓷Ba(Ti1/6Sn1/6Zr1/6Hf1/6Nb1/6Ga1/6)O3提升了近50倍。

Preparation and Dielectric Properties of Li-doped Ba(Ti1/7Sn1/7Zr1/7Hf1/7Nb1/7Ga1/7Li(1/7-x))O3 High Entropy ceramics

Recently, high entropy ceramics developed by researchers inspired by high entropy alloy have attracted wide attention, due to which can provide new design ideas for the development of non-metallic materials with excellent properties. In this work, based on perovskite ceramic BaMO3, a series of Li-doped high-entropy ceramics Ba(Ti1/7Sn1/7Zr1/7Hf1/7Nb1/7Ga1/7Li(1/7-x))O3 (x = 0, 2.3%, 5.3%, 8.3%, 11.3%) were successfully prepared by solid state reaction. The effects of Li content on the high entropy ceramic phase structure, microstructure and dielectric properties were investigated. The results show that the grain sizes of these ceramics are uniform, and the effect of Li content on the structure of ceramics is not significant. All ceramics are of cubic perovskite structure without obvious impurity phase. When x = 0, the ceramic is represented as seven-component equimolar high entropy ceramic Ba(Ti1/7Sn1/7Zr1/7Hf1/7Nb1/7Ga1/7Li1/7)O3, which exhibits excellent dielectric properties, with dielectric constant reached the maximum value of 2920 (@ 100 Hz), nearly 50 times as much as the value of Li-undoped six-component equimolar high entropy ceramic Ba (Ti1/6Sn1/6 Zr1/6 Hf1/6 Nb1/6 Ga1/6) O3.