Negative correlation between electrical response and domain size in a Ti-composition-gradient Pb [ ( Mg 1 / 3 Nb 2 / 3 <mml:…
2015; American Physical Society; Volume: 92; Issue: 17 Linguagem: Inglês
10.1103/physrevb.92.174121
ISSN1550-235X
AutoresDaisuke Shimizu, Shinya Tsukada, Masato Matsuura, Jun'ya Sakamoto, Seiji Kojima, K. Namikawa, J. Mizuki, Kenji Ohwada,
Tópico(s)Multiferroics and related materials
ResumoThe phase diagram and the relationship between the crystal coherence length and electrical response of ${\mathrm{Pb}[({\mathrm{Mg}}_{1/3}{\mathrm{Nb}}_{2/3})}_{1\ensuremath{-}x}{\mathrm{Ti}}_{x}]{\mathrm{O}}_{3}$ (PMN-$x\mathrm{PT}$) near the morphotropic phase boundary (MPB) have been precisely investigated using a single crystal with a Ti composition gradient by synchrotron x-ray diffraction and inelastic light scattering at room temperature. The crystal has two boundaries at Ti compositions of 29.0 and 34.7 mol% which correspond to the phase boundaries between the monoclinic $B ({M}_{B})$ and $C ({M}_{C})$ phases and between the ${M}_{C}$ and tetragonal $(T)$ phases, respectively. The crystal coherence length determined from the widths of Bragg peaks varies by over two orders of magnitude in a 10 mol% range of the Ti composition. It is shown that there is a strong negative correlation between the electrical response and the crystal coherence length at the sub-$\ensuremath{\mu}\mathrm{m}$ scale. The results are explained by the size effects of domains near the MPB.
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