Substrate-Independent Magnetic Bistability in Monolayers of the Single-Molecule Magnet Dy2 ScN@C80 on Metals and Insulators.

Denis S Krylov,Vasilii Dubrovin,Chia‐Hsiang Chen,Bernd Büchner,T T Nhung Nguyen,Jan Dreiser,Fupin Liu,Stanislav M Avdoshenko,Michał Studniarek,Lukas Spree,Sebastian Schimmel,Alexey A Popov,Georgios Velkos,Christian Hess,Rasmus Westerström,Claudiu Bulbucan

doi:10.1002/anie.201913955

Abstract

Magnetic hysteresis is demonstrated for monolayers of the single‐molecule magnet (SMM) Dy2ScN@C80 deposited on Au(111), Ag(100), and MgO|Ag(100) surfaces by vacuum sublimation. The topography and electronic structure of Dy2ScN@C80 adsorbed on Au(111) were studied by STM. X‐ray magnetic CD studies show that the Dy2ScN@C80 monolayers exhibit similarly broad magnetic hysteresis independent on the substrate used, but the orientation of the Dy2ScN cluster depends strongly on the surface. DFT calculations show that the extent of the electronic interaction of the fullerene molecules with the surface is increasing dramatically from MgO to Au(111) and Ag(100). However, the charge redistribution at the fullerene‐surface interface is fully absorbed by the carbon cage, leaving the state of the endohedral cluster intact. This Faraday cage effect of the fullerene preserves the magnetic bistability of fullerene‐SMMs on conducting substrates and facilitates their application in molecular spintronics.

Highlights

Single-molecule magnets (SMMs) are molecular materials exhibiting magnetic bistability and slow relaxation of magnetization.[1]
Magnetic hysteresis is demonstrated for monolayers of the single-molecule magnet (SMM) Dy2ScN@C80 deposited on Au(111), Ag(100), and MgO j Ag(100) surfaces by vacuum sublimation
DyÀN bond lengths in Dy2ScN@C80 are shorter than 2.1 ,[10b] which results in a strong uniaxial ligand field imposed by the nitride onto Dy3+ ions.[10b,13] The magnetic ground state of each Dy3+ ion is a Kramers doublet with mJ =Æ 15/2 and a quantization axis aligned along the corresponding DyÀN bond

Summary

Introduction

Endohedral metallofullerenes[8] form a special class of SMMs in which lanthanides are encapsulated within the carbon cage.[9] This allows stabilization of unusual lanthanide clusters with strong single-ion magnetic anisotropy[10] or giant exchange coupling.[11] high thermal stability of fullerenes enables formation of monolayers by sublimation.[12]. Dreiser Swiss Light Source, Paul Scherrer Institute 5232 Villigen PSI (Switzerland) [+] These authors contributed to this work. Chemie a thin film of insulator MgO grown on Ag(100), do not depend on the substrate, which highlights the robustness of fullerene SMMs and the protective function of the carbon cage

Results and Discussion

Conclusion

Conflict of interest