Constructing Asymmetrical Ni-Centered {NiN2O4} Octahedra in Layered Metal-Organic Structures for Near-Room-Temperature Single-Phase Magnetoelectricity

Kaihui Mao; Jinlei Zhang; Zijing Guo; Lizhe Liu; He Ma; Yiying Chin; Hongji Lin; Songsong Bao; Hangqing Xie; Run Yang; Zhaoyang Jing; Jiancang Shen; Guoliang Yuan; Jian Chen; Peiheng Wu; Xinglong Wu

doi:10.1021/jacs.0c05845

Constructing Asymmetrical Ni-Centered {NiN₂O₄} Octahedra in Layered Metal-Organic Structures for Near-Room-Temperature Single-Phase Magnetoelectricity

J Am Chem Soc. 2020 Jul 22;142(29):12841-12849. doi: 10.1021/jacs.0c05845. Epub 2020 Jul 10.

Authors

Kaihui Mao¹, Jinlei Zhang^{1

2}, Zijing Guo¹, Lizhe Liu¹, He Ma³, Yiying Chin⁴, Hongji Lin⁵, Songsong Bao⁶, Hangqing Xie¹, Run Yang¹, Zhaoyang Jing⁶, Jiancang Shen¹, Guoliang Yuan³, Jian Chen⁷, Peiheng Wu⁷, Xinglong Wu¹

Affiliations

¹ National Laboratory of Solid State Microstructures and Key Laboratory of Modern Acoustics, MOE, Institute of Acoustics, Nanjing University, Nanjing 210093, P. R. China.
² School and Mathematics and Physics, Suzhou University of Science and Technology, Suzhou, 215011, P. R. China.
³ School of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing 210094, P. R. China.
⁴ Department of Physics, National Chung Cheng University, Chiayi 62102, Taiwan.
⁵ National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan.
⁶ State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, P. R. China.
⁷ National Laboratory of Solid State Microstructures and Research Institute of Superconductor Electronics, Nanjing University, Nanjing 210093, P. R. China.

PMID: 32602708
DOI: 10.1021/jacs.0c05845

Abstract

Layered metal-organic structures (LMOSs) as magnetoelectric (ME) multiferroics have been of great importance for realizing new functional devices in nanoelectronics. Until now, however, achieving such room-temperature and single-phase ME multiferroics in LMOSs have proven challenging due to low transition temperature, poor spontaneous polarization, and weak ME coupling effect. Here, we demonstrate the construction of a LMOS in which four Ni-centered {NiN₂O₄} octahedra form in layer with asymmetric distortions using the coordination bonds between diphenylalanine molecules and transition metal Ni(II). Near room-temperature (283 K) ferroelectricity and ferromagnetism are observed to be both spontaneous and hysteretic. Particularly, the multiferroic LMOS exhibits strong magnetic-field-dependent ME polarization with low-magnetic-field control. The change in ME polarization with increasing applied magnetic field μ₀H from 0 to 2 T decreases linearly from 0.041 to 0.011 μC/cm² at the strongest ME coupling temperature of 251 K. The magnetic domains can be manipulated directly by applied electric field at 283 K. The asymmetrical distortion of Ni-centered octahedron in layer spurs electric polarization and ME effect and reduces spin frustration in the octahedral geometry due to spin-charge-orbital coupling. Our results represent an important step toward the production of room-temperature single-phase organic ME multiferroics.