Magnetic behaviour of TbPc2 single-molecule magnets chemically grafted on silicon surface

Abstract

Single-molecule magnets (SMMs) are among the most promising molecular systems for the development of novel molecular electronics based on the spin transport. Going beyond the investigations focused on physisorbed SMMs, in this work the robust grafting of Terbium(III) bis(phthalocyaninato) complexes to silicon surface from a diluted solution is achieved by rational chemical design yielding the formation of a partially oriented monolayer on the conducting substrate. Here, by exploiting the surface sensitivity of X-ray circular magnetic dichroism we evidence an enhancement of the magnetic bistability of this single-molecule magnet, in contrast to the dramatic reduction of the magnetic hysteresis that characterises monolayer deposits evaporated on noble and ferromagnetic metals. Photoelectron spectroscopy investigations and density functional theory analysis suggest a non-innocent role played by the silicon substrate, evidencing the potentiality of this approach for robust integration of bistable magnetic molecules in electronic devices.

Molecular lanthanide single-ion magnets: from bulk to submonolayers

“…These interactions can be weaker or completely absent if (unwanted) adsorbates are present. Wet chemistry type approaches have been demonstrated to be very successful to anchor molecular magnetic clusters, SMMs and SIMs to a variety of surfaces [21,[138][139][140][141]. This has proven to be very useful to decouple and isolate SMMs and SIMs from the surface, however, achieving direct moleculesurface electronic and magnetic coupling on purpose is rather challenging with this approach, with some few exceptions of rather inert surfaces such as Au(1 1 1) or highly oriented pyrolitic graphite (HOPG).…”

“…A recent study addresses this topic using a hydrogen-terminated Si(1 0 0) surface [141]. The TbPc 2 molecules were functionalized with long alkyl chains and chemically grafted onto the surface via the thermal hydrosilylation process.…”

The Rise of Single-Ion Magnets as Spin Qubits

“…Lanthanide-based SIMs have been intensively investigated for more than 10 years and have achieved significant progress in information storage and spintronic aspects, such as, (i) high magnetic hysteresis temperature (30 K) [62]; (ii) high magnetic anisotropic energy barrier (1000 K) [63]; and (iii) surface deposition of molecular magnets without changing the original magnetism [64][65][66][67]. In contrast, the attempts of using lanthanide-based SIMs as spin qubits have just begun [8,9,68,69].…”

Molecular Design for Single-molecule Magnetism of Lanthanide Complexes

“…From the »¤¤ peak of the cationic form 1 for an ac field of 10 3 Hz, T B is estimated to be 52 K, which is 12 K higher than those of the anionic form 2 ( Figure 5b) 0 (3) to the silicon surface reduces the electron density of the Pc rings and increase in the magnetic anisotropy of the complex with a reduction in the height of the SAP coordination polyhedron. 20 Although the T B value for complex 3 on the ) 2 ] 0 (4) noncovalently attached to CNT shows hysteresis behavior only at lower temperatures (0.04 K). 21 A possible reason for the hysteresis behavior observed at relatively high temperatures for complex 3 on the silicon surface is longitudinal contraction of the polyhedron due to surface effects, which is larger for the case of 3 on the silicon surface than for 4 on CNT.…”