http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
배지희,김준찬,김명호,이순일,Bae, Jihee,Kim, Jun Chan,Kim, Myong-Ho,Lee, Soonil 한국재료학회 2020 한국재료학회지 Vol.30 No.2
BiFeO<sub>3</sub> with perovskite structure is a well-known material that has both ferroelectric and antiferromagnetic properties called multiferroics. However, leaky electrical properties and difficulty of controlling stoichiometry due to Bi volatility and difficulty of obtaining high relative density due to high dependency on the ceramic process are issues for BiFeO<sub>3</sub> applications. In this work we investigated the sintering behavior of samples with different stoichiometries and sintering conditions. To understand the optimum sintering conditions, nonstoichiometric Bi<sub>1±x</sub>FeO<sub>3±δ</sub> ceramics and Ti-doped Bi<sub>1.03</sub>Fe<sub>1-4x/3</sub>Ti<sub>x</sub>O<sub>3</sub> ceramics were synthesized by a conventional solid-state route. Dense single phase BiFeO<sub>3</sub> ceramics were successfully fabricated using a two-step sintering and quenching process. The effects of Bi volatility on microstructure were determined by Bi-excess and Ti doping. Bi-excess increased grain size, and Ti doping increased sintering temperature and decreased grain size. It should be noted that Ti-doping suppressed Bi volatility and stabilized the BiFeO<sub>3</sub> phase.
salman,파잘 아카람,김준찬,송태권,김명호,이순일,Rizwan Ahmed Malik,Ali Hussain,김원정,성연수 한국물리학회 2019 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.75 No.10
In the present work, lead-free piezoelectric ceramics 0.65Bi1.05Fe1−xTixO3-0.35BaTi1−yNbyO3, where x = y = 0, 0.01, 0.015, 0.02, and 0.025, abbreviated as BFT-BTNb, were successfully synthesized by a solid-state reaction method and an air quenching method. The effects of B-Site donor modifications (Nb5+ and Ti4+) on the crystal structure, the morphology and the electrical properties of the 0.65BF-0.35BT ceramics were studied. X-ray diffraction patterns showed the formation of a pure perovskite structure, without any secondary phases. Scanning electron microscope (SEM) micrographs revealed that the average grain size of the BF-BT ceramics decreased with the addition of B-Site donors. Improvements in the ferroelectric properties (P-E loops) and the electric fieldinduced strain properties (S-E loops) were obtained at the optimum composition of the BFT-BTN ceramics. In addition, the dynamic piezoelectric coefficient (d ∗ 33) was enhanced from 265 pm/V for (BFT-BTNb-0) to 360 pm/V for (BFT-BTNb-1) with high working temperature, Tm = 320 ◦ C.