Magnetic Hysteresis at 10 K in Single Molecule Magnet Self‐Assembled on Gold

Abstract

Tremendous progress in the development of single molecule magnets (SMMs) raises the question of their device integration. On this route, understanding the properties of low‐dimensional assemblies of SMMs, in particular in contact with electrodes, is a necessary but difficult step. Here, it is shown that fullerene SMM self‐assembled on metal substrate from solution retains magnetic hysteresis up to 10 K. Fullerene‐SMM DySc2N@C80 and Dy2ScN@C80 are derivatized to introduce a thioacetate group, which is used to graft SMMs on gold. Magnetic properties of grafted SMMs are studied by X‐ray magnetic circular dichroism and compared to the films of nonderivatized fullerenes prepared by sublimation. In self‐assembled films, the magnetic moments of the Dy ions are preferentially aligned parallel to the surface, which is different from the disordered orientation of endohedral clusters in nonfunctionalized fullerenes. Whereas chemical derivatization reduces the blocking temperature of magnetization and narrows the hysteresis of Dy2ScN@C80, for DySc2N@C80 equally broad hysteresis is observed as in the fullerene multilayer. Magnetic bistability in the DySc2N@C80 grafted on gold is sustained up to 10 K. This study demonstrates that self‐assembly of fullerene‐SMM derivatives offers a facile solution‐based procedure for the preparation of functional magnetic sub‐monolayers with excellent SMM performance.

Exceptionally High Blocking Temperature of 17 K in a Surface‐Supported Molecular Magnet

“…This observation yields a pronounced scatter for the direction of the magnetic anisotropy axis of Dy 2 @C 80 (CH 2 Ph) on the graphene surface. [ 27 ] Furthermore, due to the presence of the side group, the molecules tend to order in a stripy pattern within the islands. Whereas these findings reflect the situation of the majority of molecules in the sample, the molecule‐substrate interaction can be better evaluated by imaging a rarely found isolated SMM on the surface.…”

“…[1][2][3] Intense research in the field of nanomagnetism within the last decade has further boosted technologically relevant performance indicators, resulting in SMMs magnetically stable above blocking temperature value not only similar to that of the bulk, but also representing the highest reported one for a molecular magnet on a surface. [25][26][27]…”

“…The analysis of the magnetic relaxation behavior of Dy 2 @C 80 (CH 2 Ph) adsorbed on graphene/Ir(111) yields a blocking temperature value not only similar to that of the bulk, but also representing the highest reported one for a molecular magnet on a surface. [ 25–27 ]…”

In silico design to enhance the barrier height for magnetization reversal in Dy(iii) sandwich complexes by stitching them under the umbrella of corannulene

“…They can also be functionalised with a tethering group to adsorb them on metallic surfaces without altering their magnetic characteristics. 26 Despite these advantages, EMFs are synthetically challenging and often suffer from very low yield, making them the world's costliest materials. 27 …”

“…They can also be functionalised with a tethering group to adsorb them on metallic surfaces without altering their magnetic characteristics. 26 Despite these advantages, EMF are synthetically challenging and often suffer from very low yield, making them the world costliest materials. 27 In search of an ideal ligand field environment that mimics dysprocenium chemistry and EMF chemistry and at the same time offers stability to the molecule under ambient conditions, we arrive at lanthanide-Corannulene moiety.…”