Aliovalent B-site modification on three- and four-layer Aurivillius intergrowth
2008; American Institute of Physics; Volume: 103; Issue: 4 Linguagem: Inglês
10.1063/1.2838486
ISSN1520-8850
AutoresWei Wang, Dan Shan, Jia-bao Sun, Xiangyu Mao, Xiaobing Chen,
Tópico(s)Multiferroics and related materials
ResumoElectrical properties of Nb-, V-, and W-doped Bi4Ti3O12–MBi4Ti4O15 (BIT-MBTi) (M=Ca,Sr) compounds were investigated. The remanent polarization (2Pr) and piezoelectric coefficient (d33) of BIT-MBTi are greatly increased by such donor doping. W-doped and Nb-doped BIT-SBTi exhibited the greatest enlargement in 2Pr and d33, respectively. Nb doping also increases 2Pr and d33 of BIT-CBTi though not that much as in the BIT-SBTi case. BIT-CBTi thin film shows a high 2Pr value of 39μC∕cm2. The enhanced properties are thought to stem from the reduced concentration and weakened mobility of oxygen vacancies. Increased activation energy of conduction further confirmed the restraint of oxygen vacancies. The different optimal V-doping content for 2Pr and d33 in BIT-SBTi might be related to the fact that V doping could affect the structure and density of domain more apparently than the concentration of oxygen vacancies. The thermal variation of dielectric constant of BIT-CBTi shows a distinctive double anomaly at 658 and 728°C. The first dielectric anomaly is related to the regulation of BIT parts, and the second one corresponds to the ferroelectric-paraelectric phase transition.
Referência(s)