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.
Fullerene single molecule magnets (SMMs) DySc2N@C80 and Dy2ScN@C80 are functionalized via a 1,3-dipolar cycloaddition with surface-anchoring thioether groups. The SMM properties of Dy-fullerenes are substantially affected by the cycloaddition. Submonolayers of the physisorbed derivatives exhibit magnetic hysteresis on an Au(111) surface at 2 K as revealed by X-ray magnetic circular dichroism.
Nanoparticle
generation by aerosol methods, particularly spark
ablation, has high potential for creating new material combinations
with tailored magnetic properties. By combining elements into complex
alloyed nanoparticles and controlling their size and structure, different
magnetic properties can be obtained. In combination with controlled
deposition, to ensure nanoparticle separation, it is possible to minimize
interparticle interactions and measure the intrinsic magnetic property
of the nanoparticles. Most magnetic materials are highly sensitive
to oxygen, and it is therefore crucial to both understand and control
the oxidation of magnetic nanoparticles. In this study, we have successfully
generated oxidized, bimetallic FeCr and FeMn nanoparticles by spark
ablation in combination with a compaction step and thoroughly characterized
individual particles with aerosol instruments, transmission electron
microscopy and synchrotron-based X-ray photoelectron spectroscopy.
The generated nanoparticles had an almost identical transition-metal
ratio to the electrodes used as seed materials. Further, we demonstrate
how the carrier gas can be used to dictate the oxidation and how to
alternate between self-passivated and entirely oxidized nanoparticles.
We also discuss the complexity of compacting alloyed nanoparticles
consisting of elements with different vapor pressures and how this
will affect the composition. This knowledge will further the understanding
of design and generation of complex alloyed nanoparticles based on
transition metals using aerosol methods, especially for the size regime
where a compaction step is needed. As a proof of concept, measurements
using a magnetometer equipped with a superconducting quantum interference
device were performed on samples with different particle coverages.
These measurements show that the magnetic properties could be explored
for both high and low surface coverages, which open a way for studies
where interparticle interactions can be systematically controlled.
Realization of stable spin states in surface-supported magnetic molecules is crucial for their applications in molecular spintronic, memory storage or quantum information processing. In this work, we studied the surface...
Tuning the anisotropy through exchange bias in bimagnetic nanoparticles is an active research strategy for enhancing and tailoring the magnetic properties for a wide range of applications. Here we present...
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