Structure and ferroelectricity of nonstoichiometric (Na0.5Bi0.5)TiO3

Abstract

The ferroelectric domain structure of pure Na 1/2 Bi 1/2 TiO 3 (NBT) and 1 at.% Mn-doped NBT (Mn-NBT) crystals was investigated by piezoresponse force microscopy. The correlation length of the polar regions was found to increase upon Mn substitution. High resolution transmission electron microscopy revealed that the coherency of the lattice across the domain boundaries between polar regions was also enhanced. Selected area electron diffraction showed that Mn favored coexisting 1/2 (ooo) and 1/2 (ooe) oxygen octahedral tiltings, over only 1/2 (ooo) for pure NBT. V C 2012 American Institute of Physics. [http://dx.

Ferroelectrics under the Synchrotron Light: A Review

“…Such is the case of some BNT-based ceramics even in the unpoled state [11,79,80]. For BNT and BNT-based and other lead-free ferroelectric ceramics, this strategy has been widely used [70,81,82,83,84,85,86,87]. …”

“…The 1D experiment is more sensitive to surface effects at low Bragg angles, which explains why one might do one or the other depending on if surface effects are the focus of the experiment. In literature, one can find informative studies that carry on Rietveld structural refinement of single conventional or synchrotron X-ray diffraction patterns with flat specimens and coupled θ–2θ scans, of ferroelectrics after the application of electric field [70,73,78,81,82,83,84,85,86,87,88,89]. …”

“…To elucidate the applicability of the three phases’ interpretation of the BNBT6 (and close compositions at the MPB) synchrotron XRD patterns [87] as an alternative to the P 4 mm tetragonal symmetry, the nature of the low-angle side humps in BNT-based ceramics [70,78,82,83,84,85,87,121] and single-crystals [122] and their dependence with respect to the main perovskite intense peaks must be clarified.…”

“…The experiment aimed to shine light on the nature of the component ascribed to the repeatedly observed humps in BNT-based ceramics [70,78,82,83,84,85,87,121] and single-crystals [122]. …”

Atomic structures of planar defects in 0.95(Na0.5Bi0.5)TiO3–0.05BaTiO3 lead-free piezoelectric thin films

“…Also, it has been reported that non-stoichiometric compositions deviated from (Na 0.5 Bi 0.5 )TiO 3 , e.g. Bi-deficient/Na-excess compositions of (Na 0.5+x Bi 0.5Àx )TiO 3+x , resulted in dramatically deteriorated ferroelectric properties and were unable to be poled to induce piezoelectric functions [8]. To date, the origins producing the property deviation remain unclear due to lack of microstructure information of the piezoelectric NBT-BT films.…”