Ordered Domains and Microwave Properties of Sub-micron Structured Ba(Zn1/3Ta2/3)O₃ Ceramics Obtained by Spark Plasma Sintering

Fei Liu; Shaojun Liu; Xuejiao Cui; Lijin Cheng; Hao Li; Jie Wang; Weidong Rao

doi:10.3390/ma12040638

Ordered Domains and Microwave Properties of Sub-micron Structured Ba(Zn_1/3Ta_2/3)O₃ Ceramics Obtained by Spark Plasma Sintering

Materials (Basel). 2019 Feb 20;12(4):638. doi: 10.3390/ma12040638.

Authors

Fei Liu^{1

2}, Shaojun Liu^{3

4}, Xuejiao Cui⁵, Lijin Cheng⁶, Hao Li⁷, Jie Wang⁸, Weidong Rao⁹

Affiliations

¹ Shenzhen Research Institute, Central South University, Shenzhen 518057, China. 163311042@csu.edu.cn.
² State Key Laboratory for Powder Metallurgy, Central South University, Changsha 410083, China. 163311042@csu.edu.cn.
³ Shenzhen Research Institute, Central South University, Shenzhen 518057, China. liumatthew@csu.edu.cn.
⁴ State Key Laboratory for Powder Metallurgy, Central South University, Changsha 410083, China. liumatthew@csu.edu.cn.
⁵ State Key Laboratory for Powder Metallurgy, Central South University, Changsha 410083, China. cxjsydl515@csu.edu.cn.
⁶ State Key Laboratory of Materials Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China. ljcheng@hust.edu.cn.
⁷ State Key Laboratory for Powder Metallurgy, Central South University, Changsha 410083, China. lihao92@csu.edu.cn.
⁸ State Key Laboratory for Powder Metallurgy, Central South University, Changsha 410083, China. zlyc135@163.com.
⁹ State Key Laboratory for Powder Metallurgy, Central South University, Changsha 410083, China. 183311055@csu.edu.cn.

Abstract

The degree of Zn²⁺ and Ta⁵⁺ ions ordering could play an important role in the dielectric loss in Ba(Zn_1/3Ta_2/3)O₃ (BZT) ceramics. However, the influence of the grain size of Ba(B'_1/3B″_2/3)O₃ ceramics with nano or sub-micron grains on the ordering domains structure is still not clear. In the present paper, highly dense (~98%) BZT microwave dielectric ceramics with homogeneous sub-micron structure (~330 nm) were prepared through spark plasma sintering (SPS). High resolution transmission electron microscopy combined with X-ray diffraction (XRD)clearly showed that the B-site ordering structure of sintered BZT samples by SPS becomes the B-site long-range 1:2 ordering as annealing proceeds. In contrast, the short-range 1:2 ordering in non-annealed counterparts was also present, which was not detectable by XRD. The size of B-site ordering domains enlarged with annealing temperature. The sub-micron structure of sintered BZT ceramics by SPS remained stable at up to 1400 C; however, the size of B-site 1:2 ordering domain was more than five times larger, which led to a significant increase of the quality factor (Q·f) to 37,700 GHz from 15,000 GHz.

Keywords: B-site ordering; domains; microwave ceramics; quality factor; spark plasma sintering; sub-micron sized grains.