High-Resolution Transmission Electron Microscopy and Computer Simulation of Defect Structures in Electronic Perovskite Ceramics.

Abstract

Defect chemistry of electronic perovskite ceramics was quite advanced by recent studies using high-resolu tion transmission electron microscopy (TEM) and computer simulation techniques. Selective site occupation of alkali-earth metal, Ca at Ruddlesden-Popper (RP) faults, causing a break of conduction pathway within a framework of corner-sharing TiO6 octahedra and improved leakage current properties, were unquestionable clarified in A-site-excess SrTiO3. Existence of meta-stable RP faults in BaTiO3 processed under thermody namically non-equilibrium condition was first empirically and then theoretically proved. Crystallographic shear (CS) structure TiO2 double layer and BaO double layer were first observed and precisely characterized in perovskite ceramics. The obtained new information about defect structure can trigger new ideas about standing reliabilityissues and should open a challenge in atomic design, based upon computer structural energy calculation in electronic perovskite materials.

Ultrahigh Energy Density of Polymer Nanocomposites Containing BaTiO3@TiO2 Nanofibers by Atomic‐Scale Interface Engineering

“…Plus, in addition to the out-of-plane polarization in [001] direction, the mutual occupation of Ba-Ti cations also gives rise to additional in-plane polarization as a result of the reduced constrain to the cation movement. [ 22,23 ] In the meantime, a larger dipolar moment could be induced by the increased tetragonality of BaTiO 3 as a result of the lattice expansion along the [001] direction. [ 24,25 ] In fact, interface engineering at the atomic scale has been adopted as a general approach to induce substantially increased electric polarization at the interface between two heterogeneous oxide thin fi lms.…”