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arXiv · 1906.07531

Discovery of room temperature ferromagnetism in metal-free organic semiconductors

Qinglin Jiang·Jiang Zhang·Zhongquan Mao·Yao Yao·Duokai Zhao·Wenqiang Zhang·Jiadong Zhou·Nan Zheng·Huanhuan Zhang·Manlin Zhao·Yong Wang·Xiaolong Li·Dehua Hu·Yuguang Ma
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Abstract

Creating magnetic semiconductors that work at warm circumstance is still a great challenge in the physical sciences. Here, we report the discovery of ferromagnetism in the metal-free perylene diimide semiconductor, whose Curie temperature is higher than 400 Kelvin. A solvothermal approach is used to reduce and dissolve the rigid-backbone perylene diimide crystallites, and radical anion aggregates were fabricated by the subsequent self-assembly and oxidation process. Magnetic measurements exhibit the ferromagnetic ordering with the saturated magnetization of 0.48 $μ_{\rm B}$ per molecule and the appreciable magnetic anisotropy. X-ray magnetic circular dichroism spectra suggest the ferromagnetism stems from $π$ orbitals of radicals. Our findings unambitiously demonstrate the long-range ferromagnetic ordering can survive at room temperature in organic semiconductors, although which are intuitively regarded to be nonmagnetic.

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Qinglin Jiang, Jiang Zhang, Zhongquan Mao, Yao Yao, Duokai Zhao, Wenqiang Zhang, Jiadong Zhou, Nan Zheng, Huanhuan Zhang, Manlin Zhao, Yong Wang, Xiaolong Li, Dehua Hu, Yuguang Ma. 2019-07-28. Discovery of room temperature ferromagnetism in metal-free organic semiconductors. https://arxiv.org/abs/1906.07531

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