Giant electromechanical coupling of relaxor ferroelectrics controlled by polar nanoregion vibrations.
Giant electromechanical coupling of relaxor ferroelectrics controlled by polar nanoregion vibrations.
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DOI：
10.1126/sciadv.1501814
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发表时间：
2016-09
期刊：
影响因子：
13.6
通讯作者：
Budai JD
中科院分区：
文献类型：
--
作者：
Manley ME;Abernathy DL;Sahul R;Parshall DE;Lynn JW;Christianson AD;Stonaha PJ;Specht ED;Budai JD
极性纳米区振动控制应用中使用的弛豫基铁电体的压电响应。基于弛豫的铁电体因其巨大的机电耦合而受到重视，并彻底改变了传感器和超声应用。压电材料的一个长期挑战是理解当响应背后的极性原子位移在弛豫基铁电体中部分分解成极性纳米区（PNR）时，这些微机电响应是如何发生的。鉴于这些材料的复杂的不均匀的纳米结构，人们通常认为，这种增强的响应必须涉及复杂的相互作用。通过使用晶格动力学和局域结构的中子散射测量，我们表明PNR的振动模式通过软化基于弛豫的铁电PMN-xPT {（1 − x）[Pb（Mg 1/3 Nb 2/3）O3] -xPbTiO 3}（x = 30%）中的底层宏畴极化旋转来实现巨耦合。该机制涉及PNR与横向声学声子的集体运动，并导致两种混合模式，一种比裸声学声子更软，一种比裸声学声子更硬。较软模态是宏观剪切软化的根源。此外，PNR模式和局部结构的组件在电场中对齐;这进一步增强了剪切软化，揭示了通过工程弹性剪切软化来调谐压电响应的方法。
Polar nanoregion vibrations control the ultrahigh piezoelectric response of relaxor-based ferroelectrics used in applications. Relaxor-based ferroelectrics are prized for their giant electromechanical coupling and have revolutionized sensor and ultrasound applications. A long-standing challenge for piezoelectric materials has been to understand how these ultrahigh electromechanical responses occur when the polar atomic displacements underlying the response are partially broken into polar nanoregions (PNRs) in relaxor-based ferroelectrics. Given the complex inhomogeneous nanostructure of these materials, it has generally been assumed that this enhanced response must involve complicated interactions. By using neutron scattering measurements of lattice dynamics and local structure, we show that the vibrational modes of the PNRs enable giant coupling by softening the underlying macrodomain polarization rotations in relaxor-based ferroelectric PMN-xPT {(1 − x)[Pb(Mg1/3Nb2/3)O3] – xPbTiO3} (x = 30%). The mechanism involves the collective motion of the PNRs with transverse acoustic phonons and results in two hybrid modes, one softer and one stiffer than the bare acoustic phonon. The softer mode is the origin of macroscopic shear softening. Furthermore, a PNR mode and a component of the local structure align in an electric field; this further enhances shear softening, revealing a way to tune the ultrahigh piezoelectric response by engineering elastic shear softening.
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影响因子：
3.7
作者：
Delaire, O.;Al-Qasir, I. I.;Berlijn, T.
通讯作者：
Berlijn, T.
影响因子：
3.5
作者：
Lagendijk, Ad;van Tiggelen, Bart;Wiersma, Diederik S.
通讯作者：
Wiersma, Diederik S.
影响因子：
64.8
作者：
Kutnjak, Z.;Petzelt, J.;Blinc, R.
通讯作者：
Blinc, R.
DOI：
10.6028/jres.117.002
发表时间：
2012
影响因子：
1.5
作者：
Lynn JW;Chen Y;Chang S;Zhao Y;Chi S;Ratcliff W 2nd;Ueland BG;Erwin RW
通讯作者：
Erwin RW
DOI：
10.1209/epl/i2005-10076-4
发表时间：
2005-07-01
期刊：
EUROPHYSICS LETTERS
影响因子：
--
作者：
Bussmann-Holder, A;Bishop, AR;Egami, T
通讯作者：
Egami, T