Crystal structure and dielectric properties of the mixed Aurivillius phase Bi7Ti4NbO21 |
| |
| Affiliation: | 1. Department of Materials Science and Engineering, National Cheng Kung University, Tainan City 70101, Taiwan;2. Center for Micro/Nano Science and Technology, National Cheng Kung University, Tainan City 70101, Taiwan;1. College of Electrical and Electronic Engineering, Anhui Science and Technology University, Bengbu, 233030, People''s Republic of China;2. Key Laboratory of Materials Physics, Institute of Solid State Physics, University of Chinese Academy of Sciences, Hefei, 230031, People''s Republic of China;3. School of Physics and Materials Science, Anhui University, Hefei, 230601, People''s Republic of China;4. College of Chemistry and Materials Engineering, Anhui Science and Technology University, Bengbu, 233030, People''s Republic of China;1. Department of Applied Physics, Birla Institute of Technology, Mesra, Ranchi, India;2. Department of Physics, Bose Institute, Kolkata, India;1. School of Materials Science and Engineering, Northeastern University, Shenyang 110189, China;2. School of Resources and Materials, Northeastern University at Qinhuangdao, Qinhuangdao 066004, China;3. Key Laboratory of Dielectric and Electrolyte Functional Materials Hebei Province, School of Resources and Materials, Northeastern University at Qinhuangdao, Qinhuangdao 066004, China;4. School of science, Inner Mongolia University of Science and Technology, Baotou 014010, China;1. UGC-DAE Consortium for Scientific Research, University Campus, Khandwa Road, Indore, 452001, India;2. Indus Synchrotrons Utilization Section, RRCAT, Indore, India;3. Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai, 400094, India |
| |
| Abstract: | The crystal structure of the ferroelectric mixed Aurivillius phase Bi7Ti4NbO21 was determined for the first time by X-ray diffractometry using a single crystal obtained by a flux method in Bi2O3 excess. It can be described as a regular stacking of double and triple perovskite-type slabs interleaved by Bi3O2 layers along the a axis. Nb is located in the double perovskite-type layers only with a random Nb/Ti distribution whereas the octahedral sites within the triple perovskite-type layers are occupied by Ti only. The thermal evolution of the dielectric constant between room temperature and 900 °C show two phase transitions at 650 and 830 °C. Combined analyses of experimental data support that the highest transition temperature corresponds to the Curie temperature, whereas the lowest one could be assigned to a phase transition within the orthorhombic symmetry by a change of the space group. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
