Enhancement of dielectric and magnetic properties in phase pure, dense BiFeO3 nanoceramics synthesized by spark plasma sintering techniques
Phase pure, dense BiFeO3 (BFO) ceramics with average grain sizes of ~ 110 nm, ~ 450 nm, and ~ 1.15 µm were fabricated by spark plasma sintering method. BFO ceramics exhibited grain-size-dependent magnetic properties, which ascribed to the antiferromagnetism–ferromagnetism (AFM–FM) transition. For BFO nanoceramics (~ 110 nm), such transition was much significant, and contributed to a large exchange bias field of HEB = 500 Oe at 5 K. In addition, BFO nanoceramics (~ 110 nm) exhibited lower leakage current and higher resistivity compared to the larger-grained BFO ceramics (~ 450 nm and ~ 1.15 µm). The calculated activation energies (Ea) and X-ray photoelectron spectroscopy analyses revealed the existence of different types of defects in BFO ceramics with different grain sizes.
This work was supported by National Natural Science Foundation of China (Grant No. 61571203), the Fundamental Research Projects of Shenzhen City: JCYJ20150831202835225. The authors acknowledge the assistance by the Analytical and Testing Center of Huazhong University of Science and Technology.
- 18.T.J. Park, G.C. Papaefthymiou, A.J. Viescas, A.R. Moodenbaugh, S.S. Wang, Nano Lett. 7, 776 (2007)Google Scholar