Spin-dependent transport properties in Pt/Fe-phthalocyanine metal-organic bilayer*

Metal-phthalocyanine complexes have been explored for their application in spintronics because of its unique magnetic properties [1]. However, investigation of the magnetic properties in phthalocyanines have been done with localized techniques such as scanning probe microscopy, and there have been few reports employing electric conduction in devices [2].
In this study, a single-crystal fcc-Pt(001)/Fe-phthalocyanine (FePc)/fcc-MgO(001) multilayer layer device was prepared and its transport property was characterized at 4 K. As a result, in addition to a quadratic normal magnetoresistance (MR), MgO/Pt/FePc/MgO shows negative MR while MgO/Pt/MgO shows positive one . The change in the MR from weak anti-localization [3] shows that FePc molecules modulated the balances between spin-orbit and phase-coherence lengths in Pt. Our results suggests that conduction electron in Pt and magnetic moment in FePt are interacted each other.
[1] N. Tsukahara et al., Phys. Rev. Lett. 102, 167203 (2009).
[2] A. Atxabal et al., Nat. Commun 7, 13751 (2016).
[3] J. Ryu et al., Phys. Rev. Lett. 116, 256802 (2016).