Ordered Domains and Microwave Properties of Sub-micron Structured Ba(Zn<sub>1/3</sub>Ta<sub>2/3</sub>)O<sub>3</sub> Ceramics Obtained by Spark Plasma Sintering
Fei Liu,
Shaojun Liu,
Xuejiao Cui,
Lijin Cheng,
Hao Li,
Jie Wang,
Weidong Rao
Affiliations
Fei Liu
Shenzhen Research Institute, Central South University, Shenzhen 518057, China
Shaojun Liu
Shenzhen Research Institute, Central South University, Shenzhen 518057, China
Xuejiao Cui
State Key Laboratory for Powder Metallurgy, Central South University, Changsha 410083, China
Lijin Cheng
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
Hao Li
State Key Laboratory for Powder Metallurgy, Central South University, Changsha 410083, China
Jie Wang
State Key Laboratory for Powder Metallurgy, Central South University, Changsha 410083, China
Weidong Rao
State Key Laboratory for Powder Metallurgy, Central South University, Changsha 410083, China
The degree of Zn2+ and Ta5+ ions ordering could play an important role in the dielectric loss in Ba(Zn1/3Ta2/3)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.
