Abstract
The use of single molecule magnets (SMMs) as cornerstone elements in spintronics and quantum computing applications demands that magnetic bistability is retained when molecules are interfaced with solid conducting surfaces. Here, we employ synchrotron Mössbauer spectroscopy to investigate a monolayer of a tetrairon(III) (Fe4) SMM chemically grafted on a gold substrate. At low temperature and zero magnetic field, we observe the magnetic pattern of the Fe4 molecule, indicating slow spin fluctuations compared to the Mössbauer timescale. Significant structural deformations of the magnetic core, induced by the interaction with the substrate, as predicted by ab initio molecular dynamics, are also observed. However, the effects of the modifications occurring at the individual iron sites partially compensate each other, so that slow magnetic relaxation is retained on the surface. Interestingly, these deformations escaped detection by conventional synchrotron-based techniques, like X-ray magnetic circular dichroism, thus highlighting the power of synchrotron Mössbauer spectroscopy for the investigation of hybrid interfaces.
Highlights
The use of single molecule magnets (SMMs) as cornerstone elements in spintronics and quantum computing applications demands that magnetic bistability is retained when molecules are interfaced with solid conducting surfaces
Most investigations rely on the use of Xray absorption and magnetic circular dichroism (XMCD)[15] with synchrotron radiation, which has exceptional surface sensitivity and selectivity to the magnetism of the probed elements
A monolayer deposit was obtained by chemisorption using a wet chemistry protocol that guarantees the formation of a dense monolayer with no physisorbed material[28]
Summary
The use of single molecule magnets (SMMs) as cornerstone elements in spintronics and quantum computing applications demands that magnetic bistability is retained when molecules are interfaced with solid conducting surfaces. In silico methods can be of considerable aid in predicting the fine evolution of geometrical and magnetic structure of SMMs on a surface[16] In such a framework, Mössbauer spectroscopy, beyond having an outstanding sensitivity to the coordination environment of the probed atom, is able to investigate the spin dynamics over timescales (1–1000 ns) much shorter than those accessible by XMCD. This limitation was overcome by the use of time-domain nuclear resonant scattering of synchrotron radiation at grazing angle: an example was the study of monolayers of metallic 57Fe grown on W(100) or embedded in layered systems[20,21,22] With this technique complex spectra are expected for samples containing inequivalent iron sites and characterized by several electronic levels. Thanks to the outstanding sensitivity of this spectroscopy to the coordination environment of the probed atom, we have evidenced that molecules on surface undergo significant structural deformations, which are undetectable by
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
