Origin of large ferroelectric polarization enhancement under high-pressure for multiferroic DyMnO3 revealed by polarized and unpolarized neutron diffraction
Origin of large ferroelectric polarization enhancement under high-pressure for multiferroic DyMnO3 revealed by polarized and unpolarized neutron diffraction
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偏振和非偏振中子衍射揭示多铁性 DyMnO3 在高压下大铁电极化增强的起源
DOI：
10.1103/physrevb.102.085131
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发表时间：
2020
影响因子：
3.7
通讯作者：
T. Osakabe
中科院分区：
文献类型：
--
作者：
N. Terada;N. Qureshi;A. Stunault;M. Enderle;B. Ouladdiaf;C. Colin;D.D. Khalyavin;P. Manuel;F. Orlandi;S. Miyahara;D. Prabhakaran;T. Osakabe
多铁性钙钛矿型稀土锰氧化物(Tb，Gd)是一种表现出压致巨大铁电极化的多铁性材料。在这项研究中，我们通过中子衍射和球面中子偏振(SNP)实验研究了压力感生相中的磁序，最高可达8.0 GPa.Mn自旋的磁有序性由无公度摆线转变为公度共线型结构，KmN=0，12，0高于4.0 GPa.伴随着巨铁电极化的出现.Dy自旋的磁序被确定为含有自旋和自旋分量的非共线自旋结构，对于低和高压相，kDy=(0，12，0)。沿轴的磁场影响Dy的排序，这从k向量从kDy=(0，12，0)到kDy=(0，0，0)in的变化中可以看出。考虑到所确定的磁序通过交换伸缩机制产生的晶格扭曲，我们得出结论：稀土和锰键的交换伸缩与稀土锰氧化物高压相铁电极化的显著磁场增强密切相关。
The multiferroic perovskite rare earth manganites(, Tb, Gd) are known as multiferroics exhibiting pressure-induced gigantic ferroelectric polarization. In this study, we have investigated the magnetic orderings in the pressure-induced phases for, by neutron diffraction and spherical neutron polarimetry (SNP) experiments up to 8.0 GPa. The magnetic ordering for Mn spins changes from the incommensurate-cycloid to the commensurate collinear-type structure with kMn=0,12,0 above 4.0 GPa, which is concomitant with the appearance of a giant ferroelectric polarization. The magnetic ordering for the Dy spins has been determined to be a noncollinear spin structure withandspin components and kDy=(0,12,0) for the low- and high-pressure phases. The magnetic field along theaxis,, affects the Dy ordering, which is seen in the changes in the k vector from kDy=(0,12,0) into kDy=(0,0,0) in. Considering the lattice distortion generated by the determined magnetic orderings through the exchange striction mechanism, we conclude that the exchange striction for rare earth and Mn bonds, which is added to the uniform polarization generated by the-type Mn ordering, is strongly related to the significant magnetic field enhancement of ferroelectric polarization in the high-pressure phase of the rare earth manganites.