Jin Cai, Zhu Yuanmin, Li Xiaowen, An Feng, Han Wenqiao, Liu Qi, Hu Sixia, Ji Yanjiang, Xu Zedong, Hu Songbai, Ye Mao, Zhong Gaokuo, Gu Meng, Chen Lang
Department of Physics, Southern University of Science and Technology, Shenzhen, 518055, China.
School of Physics, Harbin Institute of Technology, Harbin, 150081, China.
Adv Sci (Weinh). 2021 Dec;8(24):e2102178. doi: 10.1002/advs.202102178. Epub 2021 Oct 28.
Multiferroic materials with flexibility are expected to make great contributions to flexible electronic applications, such as sensors, memories, and wearable devices. In this work, super-flexible freestanding BiMnO membranes with simultaneous ferroelectricity and ferromagnetism are synthesized using water-soluble Sr Al O as the sacrificial buffer layer. The super-flexibility of BiMnO membranes is demonstrated by undergoing an ≈180° folding during an in situ bending test, which is consistent with the results of first-principles calculations. The piezoelectric signal under a bending radius of ≈500 µm confirms the stable existence of electric polarization in freestanding BiMnO membranes. Moreover, the stable ferromagnetism of freestanding BiMnO membranes is demonstrated after 100 times bending cycles with a bending radius of ≈2 mm. 5.1% uniaxial tensile strain is achieved in freestanding BiMnO membranes, and the piezoresponse force microscopy (PFM) phase retention behaviors confirm that the ferroelectricity of membranes can survive stably up to the strain of 1.7%. These super-flexible membranes with stable ferroelectricity and ferromagnetism pave ways to the realizations of multifunctional flexible electronics.
具有柔韧性的多铁性材料有望为柔性电子应用做出巨大贡献，如传感器、存储器和可穿戴设备。在这项工作中，使用水溶性SrAlO作为牺牲缓冲层合成了同时具有铁电性和铁磁性的超柔性独立式BiMnO膜。BiMnO膜的超柔韧性通过原位弯曲测试中的约180°折叠得到证明，这与第一性原理计算结果一致。在约500 µm的弯曲半径下的压电信号证实了独立式BiMnO膜中极化的稳定存在。此外，独立式BiMnO膜在约2 mm弯曲半径下经过100次弯曲循环后仍表现出稳定的铁磁性。独立式BiMnO膜实现了5.1%的单轴拉伸应变，压电力显微镜（PFM）相保留行为证实了膜的铁电性在高达1.7%的应变下仍能稳定存在。这些具有稳定铁电性和铁磁性的超柔性膜为实现多功能柔性电子器件铺平了道路。
