Anisotropy of ferroelectric behavior of (1 − x)Bi1/2Na1/2TiO3–xBaTiO3 single crystals across the morphotropic phase boundary
Anisotropy of ferroelectric behavior of (1 − x)Bi1/2Na1/2TiO3–xBaTiO3 single crystals across the morphotropic phase boundary
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DOI：
10.1063/1.4891529
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发表时间：
2014-07
影响因子：
3.2
通讯作者：
D. Schneider;W. Jo;J. Rödel;D. Rytz;T. Granzow
中科院分区：
文献类型：
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作者：
D. Schneider;W. Jo;J. Rödel;D. Rytz;T. Granzow
通过顶部籽晶溶液生长，生长具有三种不同组成的（1-x）（Bi 1/2Na 1/2）TiO 3-xBaTiO 3（BNT-100 xBT）单晶，x = 0.036、0.065和0.088，覆盖相图的菱形到主要为四面体的区域，并包含准同型相界（MPB）。介电和铁电测量进行了不同的取向相对于晶轴的样品。虽然结果符合目前的理解的晶体结构，没有增强的机电性能的基础上的瞬态极化旋转观察。这清楚地将BNT-100 xBT与其他具有菱形-四面体MPB的弛豫铁电系统（如（1-x）Pb（Mg 1/3 Nb 2/3）O3-xPbTiO 3）区分开来。观察到一个异常的极化行为中的应变在BNT-100 xBT在紧邻的MPB与x = 0.065，导致在一个巨大的小信号压电系数d 33的4600 pm/V。这种效果被假设是由于一个不可逆的相变从菱面体极性纳米区域到四面体铁电微畴。
(1 − x)(Bi1/2Na1/2)TiO3-xBaTiO3 (BNT-100xBT) single crystals with three different compositions of x = 0.036, 0.065, and 0.088, covering the rhombohedral to predominantly tetragonal region of the phase diagram and encompassing the morphotropic phase boundary (MPB), were grown by top-seeded solution growth. Dielectric and ferroelectric measurements were performed on samples with different orientations with respect to the crystallographic axes. While the results complied with the current understanding of the crystallographic structure, no enhancement of electromechanical properties based on transient polarization rotation was observed. This clearly sets BNT-100xBT apart from other relaxor ferroelectric systems with a rhombohedral-tetragonal MPB such as (1 − x) Pb(Mg1/3Nb2/3)O3-xPbTiO3. An anomaly was observed in the poling behavior of the strain in 〈001〉 oriented BNT-100xBT in the immediate vicinity of the MPB with x = 0.065, resulting in a giant small-signal piezoelectric coefficient d 33 of 4600 pm/V. This effect is hypothesized to be due to an irreversible phase change from rhombohedral polar nanoregions to tetragonal ferroelectric microdomains.