Enhanced Magnetic Anisotropy via Quasi-Molecular Magnet at Organic-Ferromagnetic Contact.
To realize the origin of efficient spin injection at organic-ferromagnetic contact in organic spintronics, we have implemented the formation of quasi-molecular magnet via surface restructuring of a strong organic acceptor, tetrafluoro-tetracyano-quinodimethane (F4-TCNQ), in contact with ferromagnetic cobalt. Our results demonstrate a spin-polarized F4-TCNQ layer and a remarkably enhanced magnetic anisotropy of the Co film. The novel magnetic properties are contributed from strong magnetic coupling caused by the molecular restructuring that displays an angular anchoring conformation of CN and upwardly protruding fluorine atoms. We conclude that the π bonds of CN, instead of the lone-pair electrons of N atoms, contribute to the hybridization-induced magnetic coupling between CN and Co and generate a superior magnetic order on the surface.
†National Synchrotron Radiation Research Center, Hsinchu, 30076, Taiwan, R.O.C.|∥Department of Photonics, National Cheng Kung University, Tainan 701, Taiwan, R.O.C.
Yao-Jane
YJ
Hsu
†National Synchrotron Radiation Research Center, Hsinchu, 30076, Taiwan, R.O.C.
Yu-Ling
YL
Lai
†National Synchrotron Radiation Research Center, Hsinchu, 30076, Taiwan, R.O.C.
Chih-Han
CH
Chen
†National Synchrotron Radiation Research Center, Hsinchu, 30076, Taiwan, R.O.C.
Ying-Chang
YC
Lin
‡Department of Chemistry, National Taiwan Normal University, Taipei, 11677, Taiwan, R.O.C.
Hsiu-Yun
HY
Chien
‡Department of Chemistry, National Taiwan Normal University, Taipei, 11677, Taiwan, R.O.C.
Jeng-Han
JH
Wang
§Institute of Nano Technology, National Chiao Tung University, Hsinchu, 30010, Taiwan, R.O.C.
Tu-Ngoc
TN
Lam
†National Synchrotron Radiation Research Center, Hsinchu, 30076, Taiwan, R.O.C.
Yuet-Loy
YL
Chan
†National Synchrotron Radiation Research Center, Hsinchu, 30076, Taiwan, R.O.C.
D H
DH
Wei
†National Synchrotron Radiation Research Center, Hsinchu, 30076, Taiwan, R.O.C.
Hong-Ji
HJ
Lin
†National Synchrotron Radiation Research Center, Hsinchu, 30076, Taiwan, R.O.C.
Chien-Te
CT
Chen
charge-transfer; interface; magnetic coupling; molecular restructuring; organic spintronics; spin polarization