Paper SS+AS+MI-MoM5
X-ray Microscopy and Spectroscopy Insights of Metal-Organics Contacts

Monday, October 30, 2017, 9:40 am, Room 25

Abstract

After the giant magnetoresistance (GMR) was demonstrated in Co/Alq₃/LSMO trilayers [1], the rise of organic spintronics was no longer a question of if, but when. Latter it was even suggested that the interfaces are the most critical players toward the success of organic spinronics [2]. Unfortunately, despite much effort, vertical organic spin valve (OSV) could not establish a meaningful GMR at room temperature unless a thin insulator film is inserted between the ferromagnetic electrode and organic spacer [3-5]. Calls for spectroscopic studies were thus made to improve or even scrutinize the existing understandings [6]. In this report, I describe a jointed X-ray microscopy and spectroscopy investigations on multiple ferromagnet-organic hybrid structures including Co/pentacene, Fe/C₆₀, Co/C₆₀, and Ni/C₆₀. Our study indicates that the ferromagnetic (FM) 3d transition metals land on organic semiconductor (OSC) films suffer an apparent magnetization retardation. Further investigation reveals that there is more than a reactive interface behind the scenes. Finally, the connection between our findings and reported transport measurements is addressed.

Acknowledgments

Financial supports from Minister of Science and Technology (MoST) and National Synchrotron Radiation Research Center at Taiwan are greatly acknowledged.

References

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[4] - M. Gobbi, F. Golmar, R. Llopis, F. Casanova, Fèlix, and L. E. Hueso, Adv. Mater.23, 1609 (2011).

[5] - X. Zhang, S. Mizukami, T. Kubota, Q. Ma, M. Oogane, H. Naganuma, Y. Ando, and T. Miyazaki, Nat. Comm.4, 1392 (2013).