Abstract Spin cross-over molecules show the unique ability to switch between two spin states when submitted external stimuli such as temperature, light or voltage. If controlled at molecular scale, switches would be of great interest for development genuine devices in spintronics, sensing and nanomechanics. Unfortunately, up now, little is known on behaviour organized dimensions their cooperative transformation. Here we demonstrate that a combination scanning tunnelling microscopy...

We demonstrate that a ${\mathrm{C}}_{60}$ overlayer enhances the perpendicular magnetic anisotropy of Co thin film, inducing an inverse spin reorientation transition from in plane to out plane. The driving force is ${\mathrm{C}}_{60}/\mathrm{Co}$ interfacial we have measured quantitatively situ as function coverage. Comparison with state-of-the-art ab initio calculations show this mainly arises local hybridization between ${p}_{z}$ and ${d}_{{z}^{2}}$ orbitals. By generalizing these...

Abstract Understanding the modification of graphene’s electronic structure upon doping is crucial for enlarging its potential applications. We present a study nitrogen-doped graphene samples on SiC(000"Equation missing"<!-- image only, no MathML or LaTex -->) combining angle-resolved photoelectron spectroscopy, scanning tunneling microscopy and spectroscopy X-ray (XPS). The comparison between spectra reveals spatial inhomogeneity Dirac energy shift that phonon correction has to be applied...

The temperature and concentration dependences of the self-assembly onto graphite from solution a series molecular building blocks able to form nanoporous structures are analyzed experimentally by in situ scanning tunneling microscopy. It is shown that commonly observed coexistence dense domains results kinetic blockades rather than thermodynamic equilibrium. ripening can be favored high densities domain boundaries, which obtained cooling substrate before nucleation growth. Then at...

The chemical doping of graphene is a promising route to improve the performances graphene-based devices through enhanced reactivity, catalytic activity, or transport characteristics. Understanding interaction molecules with doped at atomic scale therefore leading challenge be overcome for development electronics and sensors. Here, we use scanning tunneling microscopy spectroscopy study electronic pristine nitrogen-doped self-assembled tetraphenylporphyrin molecules. We provide an extensive...

Spin-crossover molecules are very appealing for use in multifunctional spintronic devices because of their ability to switch between high-spin and low-spin states with external stimuli such as voltage light. In actual devices, the deposited on a substrate, which can modify properties. However, surprisingly little is known about molecule-substrate effects. Here we show first time, by grazing incidence X-ray diffraction, that an FeII spin-crossover molecular layer displays well-defined...

Abstract Light‐induced spin‐state switching is one of the most attractive properties spin‐crossover materials. In bulk, low‐spin (LS) to high‐spin (HS) conversion via light‐induced excited trapping (LIESST) effect may be achieved with a visible light, while HS‐to‐LS (reverse‐LIESST) requires an excitation in near‐infrared range. Now, it shown that those phenomena are strongly modified at interface metal. Indeed, anomalous spin presented from HS state LS under blue light illumination for Fe...

Decoupling the electronic properties of a molecule from substrate is crucial importance for development single-molecule electronics. This achieved here by adsorbing pentacene molecules at low temperature on hydrogenated Si(100) surface (12 K). The (5 K) scanning tunneling microscope (STM) topography single energy highest occupied molecular orbital (HOMO) tunnel resonance clearly resembles native HOMO free molecule. negligible coupling between and confirmed theoretical STM diffusion barrier...

The hysteretic spin transition of a 130 nm-thick film becomes quantitative by annealing the co-crystallized metastable phase.

Among switchable molecules, spin-crossover molecules are particularly appealing for molecular electronics as their change in spin state is associated with a large conductance and can also be used spintronic devices. In this article, we review the techniques that allow one to measure electronic transport through single molecules. We emphasize recent experiments using scanning tunneling microscopy spectroscopy, where controlled by electric field, current or light. Les molécules à transition de...

Spin-crossover molecules are very attractive compounds to realize multifunctional spintronic devices. Understanding their properties when deposited on metals is therefore crucial for future rational implementation as ultrathin films in such Using X-ray absorption spectroscopy, we study the thermal transition of spin-crossover compound FeII((3,5-(CH3)2Pz)3BH)2 from submonolayer multilayers a Cu(111) substrate. We determine how residual fraction high spin at low temperature, well bistability...

The reversible hopping of a bistable atom on the Si(100)-(2×1):H surface is activated nonlocally by hole injection into Si-Si bond states with low temperature (5 K) scanning tunneling microscope. In contact region, at short distances (<1.5 nm) between site and atom, yield exhibits remarkable variations as function site. It explained density state distribution along silicon network that shows charge-transfer pathways sites atom.

Understanding the properties of spin-crossover molecules in direct contact with metals is crucial for their future integration electronic and spintronic devices. By X-ray absorption spectroscopy, we investigate FeII((3,5-(CH3)2Pz)3BH)2 form monolayer islands on a metallic substrate, namely, Au(111). We demonstrate that transition can be thermally induced from high spin state to mixed phase containing one-third high-spin-state two-thirds low-spin-state agreement previous work by scanning...

Bistable spin-crossover molecules are particularly interesting for the development of innovative electronic and spintronic devices as they present two spin states that can be controlled by external stimuli. In this paper, we report voltage-induced switching high spin/low self-assembled in dense 2D networks on Au(111) Cu(111) scanning tunneling microscopy at low temperature. On Au(111), voltage pulses lead to nonlocal from any─high or low─spin state other followed a spontaneous relaxation...

We present a comparative study of the electronic properties clean Si(100) and hydrogenated Si(100):H surfaces performed with low-temperature (5 K) scanning tunneling microscope. Various surface structures such as single silicon dangling bonds bare dimers created by local desorption hydrogen atoms from are also investigated. The experimental spectroscopy (STS) curves acquired locally on each these compared STS measurements surfaces. First principle density-functional theory calculations...

The ultimate miniaturization of electronic devices at the atomic scale with single electrons requires controlling reversible charge storage in a atom. However, is difficult to control as usually only one state can be stabilized. Here, combining scanning tunneling microscopy (STM) and density functional theory (DFT), we demonstrate that silicon dangling bond hydrogenated $p$-type doped Si(100) surface has two stable states (neutral negatively charged) low temperature (5 K). Reversible...

We measure by means of in situ magneto-optical Kerr effect the magnetism ultrathin magnetic films supported on gold and platinum during capping with molecular layers. observe both for ${\mathrm{C}}_{60}$ ${\mathrm{Alq}}_{3}$ molecules deposited Co an enhancement out-of-plane anisotropy, leading to a hardening magnetization. Surprisingly, amplitude this depends strongly underlying substrate. While we find increase coercive field around 100% Co/Au(111), it can reach almost 600% Co/Pt(111)....

In this paper, we discuss in the framework of a mechanoelastic model electronic and mechanical behavior single layer spin crossover molecules self-organized on substrate. We consider situated face-centered-cubic structure interacting between with sites substrate by way connecting springs given elastic constants. The main experimental results are reproduced, i.e., typical thermal transitions their incompleteness hysteresis loop, residual fractions after low-temperature relaxations,...

Abstract The combination of graphene with molecules offers promising opportunities to achieve new functionalities. In these hybrid structures, interfacial charge transfer plays a key role in the electronic properties and thus has be understood mastered. Using scanning tunneling microscopy ab initio density functional theory calculations, we show that combining nitrogen doping an electric field allows for selective control state molecular layer on graphene. On pristine graphene, local gating...

Spin-crossover molecules present the unique property of having two spin states that can be controlled by light excitation at low temperature. Here, we report on photoexcitation [FeII((3, 5-(CH3)2Pz)3BH)2] (Pz = pyrazolyl) ultrathin films, with thicknesses ranging from 0.9 to 5.3 monolayers, adsorbed Cu(111) substrate. Using X-ray absorption spectroscopy measurements, confirm anomalous light-induced spin-state switching observed for sub-monolayer coverage and demonstrate it is confined first...

Surface reconstructions on the hydrogenated Si(100):H surface are observed and investigated by using a low-temperature (5 K) scanning tunneling microscope (STM). In addition to well established $2\ifmmode\times\else\texttimes\fi{}1$ $3\ifmmode\times\else\texttimes\fi{}1$ phases, linear structures extending over one six silicon dimers along same dimer row observed. After careful analysis of corresponding STM topographies for both $n$-type $p$-type doped substrates, we conclude that these...

We study the magnetic domain wall structure in bilayers (two ultrathin ferromagnetic layers separated by a non spacer) with perpendicular magnetization. Combining force and ballistic electron emission microscopies, we are able to reveal details of high spatial accuracy. In these layers, show that classical Bloch observed single transforms into superposed N\'eel walls due coupling between layers. Quantitative agreement micromagnetic calculations is achieved.

Free-base porphyrin molecules offer appealing options to tune the interaction with their environment via manipulation of inner hydrogen atoms and molecular conformation. Using scanning tunneling microscopy we show, through a systematic study, that conformation, electronic gap, wave function, molecule-substrate are modified by switch or removal. Experimental results in combination ab initio calculations provide an understanding underlying physical process.

Scanning tunneling microscopy experiments have been performed to measure the local electron injection in nitrogen-doped graphene on $\text{SiC}(000\overline{1})$ and were successfully compared ab initio calculations. In graphene, a gaplike feature is measured around Fermi level due phonon-mediated channel. At nitrogen sites, this vanishes an increase of elastic channel that allowed because symmetry breaking induced by atoms. A large conductance enhancement factor up 500 was at comparing...