Liu Mei Ying, Yu Jun Xi, Zhu Xiao Li, Bian Zhi Ping, Zhou Xiang, Liang Yu Hang, Luo Zhen Lin, Yin Yue Wei, Li Jiang Yu, Chen Xiang Ming
School of Materials Science and Engineering, Zhejiang University, Hangzhou310027, China.
Institute for Advanced Study, Chengdu University, Chengdu610100, China.
ACS Appl Mater Interfaces. 2022 Nov 23;14(46):52117-52123. doi: 10.1021/acsami.2c11927. Epub 2022 Nov 8.
The hexagonal rare earth ferrites -RFeO(R = rare earth element) have been recognized as promising candidates for a room-temperature multiferroic system, and the primary issue for these materials is how to get a stable hexagonal structure since the centrosymmetric orthorhombic structure is generally stable for most RFeO at room-temperature, while the hexagonal phase is only stable under some strict conditions. In the present work, -LuInFeO ( = 0-1) thin films were prepared on a Nb-SrTiO (111) single-crystal substrate by a pulsed laser deposition (PLD) process, and the multiferroic characterization was performed at room temperature. With the combined effects of chemical pressure and epitaxial strain, the stable hexagonal structure was achieved in a wide composition range ( = 0.5-0.7), and the results of XRD (X-ray diffraction) and SAED (selected area electron diffraction) indicate the super-cell match relations between the -LuInFeO thin film and substrate. The saturated - hysteresis loop was obtained at room temperature with a remanent polarization of about 4.3 μC/cm, and polarization switching was also confirmed by PFM measurement. Furthermore, a strong magnetoelectric coupling with a linear magnetoelectric coefficient of 1.9 V/cm Oe was determined, which was about three orders of magnitude larger than that of -RFeO ceramics. The present results indicate that the -LuInFeO thin films are expected to have great application potential for magnetoelectric memory and detection devices.
六方稀土铁氧体-RFeO（R = 稀土元素）被认为是室温多铁性体系的有潜力候选材料，对于这些材料来说，主要问题是如何获得稳定的六方结构，因为对于大多数RFeO而言，中心对称的正交结构在室温下通常是稳定的，而六方相仅在某些严格条件下才稳定。在本工作中，通过脉冲激光沉积（PLD）工艺在Nb-SrTiO（111）单晶衬底上制备了-LuInFeO（= 0 - 1）薄膜，并在室温下进行了多铁性表征。在化学压力和外延应变的共同作用下，在较宽的成分范围（= 0.5 - 0.7）内实现了稳定的六方结构，XRD（X射线衍射）和SAED（选区电子衍射）结果表明-LuInFeO薄膜与衬底之间存在超胞匹配关系。在室温下获得了饱和-磁滞回线，剩余极化约为4.3 μC/cm，PFM测量也证实了极化切换。此外，确定了具有1.9 V/cm Oe线性磁电系数的强磁电耦合，这比-RFeO陶瓷的磁电系数大约大三 orders of magnitude。本结果表明-LuInFeO薄膜有望在磁电存储和检测器件方面具有巨大的应用潜力。
