Department of Physics, Southeast University, Nanjing 211189, China.
National Laboratory of Solid State Microstructures and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China.
Phys Rev Lett. 2014 Oct 31;113(18):187204. doi: 10.1103/PhysRevLett.113.187204.
The iron selenides are important because of their superconducting properties. Here, an unexpected phenomenon is predicted to occur in an iron-selenide compound with a quasi-one-dimensional ladder geometry: BaFe(2)Se(3) should be a magnetic ferrielectric system, driven by its magnetic block order via exchange striction. A robust performance (high T(C) and large polarization) is expected. Different from most multiferroics, BaFe(2)Se(3) is ferrielectric, with a polarization that mostly cancels between ladders. However, its strong magnetostriction still produces a net polarization that is large (∼0.1 μC/cm(2)) as compared with most magnetic multiferroics. Its fully ferroelectric state, with energy only slightly higher than the ferrielectric, has a giant improper polarization ∼2-3 μC/cm(2).
铁硒化物因其超导性能而备受关注。在这里，人们预测在具有准一维梯型结构的铁硒化物化合物中会出现一种意想不到的现象：BaFe(2)Se(3)应该是一个通过交换压缩驱动的铁磁铁电体系。人们预计它会具有良好的性能（高 T(C)和大的极化强度）。与大多数多铁性材料不同，BaFe(2)Se(3)是铁电体，其在梯型结构之间的极化强度大部分相互抵消。然而，其强磁致伸缩仍然会产生一个大的净极化强度（∼0.1 μC/cm(2)），这比大多数磁性多铁性材料都要强。其完全铁电态的能量仅略高于铁电态，具有一个巨大的非理想极化强度∼2-3 μC/cm(2)。
