Jia Wen Song, Yuan Gao, Yi Bang Ou, Xiang Tao Luo, Xing Yu Chen, Wen Ya Wang, Ying Wang, Shu Ya Wu, Xiao Qiang Liu, Xiao Li Zhu, He Tian, Xiang Ming Chen
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引用次数: 0
Abstract
The role of incommensurate (IC) modulation in the evolution of the pinched polarization–electric field (P–E) hysteresis loops has been investigated and discussed based on the structure and polarization evolution in Ba4(Sm1–xLax)2Ti4Nb6O30 tetragonal tungsten bronzes. The relaxor behavior in the La-rich compound is accompanied by an IC modulation structure. Introduction of smaller Sm in the system increases the driving force for the transition from an IC modulation structure to a commensurate superstructure, which coupled with the ferroelectric transition in the middle composition with x = 0.5. In the Sm-rich compounds, the IC modulation structure reappears as a metastable state to balance the structural instability caused by the too small average ionic radius of the rare-earth ion; meanwhile, the field-induced transition from the IC modulation structure to the commensurate superstructure is confirmed by selected area electron diffraction using an in situ bias technique as the structural origin for the pinched P–E loops. A phase diagram has been established by combining the ferroelectric phase transition and the modulation structure transition, and a new region with both very small A-site size (A1 + A2)/2 and A1-site tolerance factor (tA1) related to the ferroelectric compounds with pinched P–E loops (pinched FE) was added into the previously reported crystal-chemical framework (Chem. Mater.2015,27, 3250–3261). The present work expands the composition–structure–property relationships in tungsten bronze ferroelectrics by including the recently reported “pinched FE” and meanwhile extends the composition manipulation ranges from the crossover between relaxor and normal ferroelectrics to ferroelectrics with pinched P–E loops.
期刊介绍:
The journal Chemistry of Materials focuses on publishing original research at the intersection of materials science and chemistry. The studies published in the journal involve chemistry as a prominent component and explore topics such as the design, synthesis, characterization, processing, understanding, and application of functional or potentially functional materials. The journal covers various areas of interest, including inorganic and organic solid-state chemistry, nanomaterials, biomaterials, thin films and polymers, and composite/hybrid materials. The journal particularly seeks papers that highlight the creation or development of innovative materials with novel optical, electrical, magnetic, catalytic, or mechanical properties. It is essential that manuscripts on these topics have a primary focus on the chemistry of materials and represent a significant advancement compared to prior research. Before external reviews are sought, submitted manuscripts undergo a review process by a minimum of two editors to ensure their appropriateness for the journal and the presence of sufficient evidence of a significant advance that will be of broad interest to the materials chemistry community.