Kim Jong Hyuk, Jeong Ki Won, Oh Dong Gun, Shin Hyun Jun, Hong Jae Min, Kim Jin Seok, Moon Jae Young, Lee Nara, Choi Young Jai
Department of Physics, Yonsei University, Seoul, 03722, Korea.
Sci Rep. 2021 Dec 10;11(1):23786. doi: 10.1038/s41598-021-03330-8.
Double-perovskite multiferroics have been investigated because alternating orders of magnetic ions act as distinct magnetic origins for ferroelectricity. In YbCoMnO, the frustrated antiferromagnetic order emerging at T = 52 K induces ferroelectric polarization perpendicular to the c axis through cooperative O shifts via the symmetric exchange striction. In our detailed measurements of the magnetoelectric properties of single-crystalline YbCoMnO, we observe full ferromagnetic-like hysteresis loops that are strongly coupled to the dielectric constant and ferroelectric polarization at various temperatures below T. Unlike LuCoMnO with non-magnetic Lu ions, we suggest the emergence of additional ferroelectric polarization along the c axis below the ordering temperature of magnetic Yb ions, T ≈ 20 K, based on the spin structure established from recent neutron diffraction experiments. While the proposed description for additional ferroelectricity, ascribed to the symmetric exchange striction between Yb and Co/Mn magnetic moments, is clearly given, anomalies of dielectric constants along the c axis are solely observed. Our interesting findings on magnetoelectric hysteresis and the possible development of additional ferroelectricity reveal notable characteristics of double perovskites and provide essential guidance for the further examination of magnetoelectric functional properties.
双钙钛矿多铁性材料已被研究，因为磁性离子的交替排列作为铁电性的不同磁起源。在YbCoMnO中，在T = 52 K出现的受挫反铁磁序通过对称交换约束引起的协同O位移诱导垂直于c轴的铁电极化。在我们对单晶YbCoMnO磁电性质的详细测量中，我们观察到在低于T的各种温度下与介电常数和铁电极化强烈耦合的完全类似铁磁的磁滞回线。与具有非磁性Lu离子的LuCoMnO不同，基于最近中子衍射实验建立的自旋结构，我们认为在磁性Yb离子的有序温度T≈20 K以下，沿c轴出现了额外的铁电极化。虽然明确给出了归因于Yb与Co/Mn磁矩之间对称交换约束的额外铁电性的提议描述，但仅观察到沿c轴的介电常数异常。我们关于磁电滞回的有趣发现以及额外铁电性的可能发展揭示了双钙钛矿的显著特征，并为进一步研究磁电功能特性提供了重要指导。
