We report that the Kondo effect exerted by a magnetic ion depends on its chemical environment. A cobalt phthalocyanine molecule adsorbed an Au111 surface exhibited no effect. Cutting away eight hydrogen atoms from with voltage pulses scanning tunneling microscope tip allowed four orbitals of this to chemically bond gold substrate. The localized spin was recovered in artificial molecular structure, and clear resonance observed near Fermi surface. attribute high temperature (more than 200...

The chemical reactivity of different surfaces titanium dioxide (TiO2) has been the subject extensive studies in recent decades. anatase TiO2(001) and its (1 × 4) reconstructed were theoretically considered to be most reactive have heavily pursued by synthetic chemists. However, lack direct experimental verification or determination active sites on these caused controversy debate. Here we report a systematic study an TiO2(001)-(1 surface means microscopic spectroscopic techniques combination...

Joint strategy for surface chemistry Recent advances in the development of tip-based microscopy have led to angstrom-scale spatial resolution, but no technique provides univocal characterization structural and chemical heterogeneities species. Using a model system pentacene derivatives on Ag(110) surface, Xu et al. show that combination scanning tunneling microscopy, atomic force tip-enhanced Raman scattering electronic, structural, information sufficiently correlated an unambiguous...

The water splitting reaction based on the promising TiO(2) photocatalyst is one of fundamental processes that bears significant implication in hydrogen energy technology and has been extensively studied. However, a long-standing puzzling question understanding sequence whether initial step photocatalytic process how it happens. Here, using low temperature scanning tunneling microscopy (STM) performed at 80 K, we observed dissociation individually adsorbed molecules 5-fold coordinated Ti...

A knowledge of adsorption behaviors oxygen on the model system reduced rutile TiO(2)(110)-1×1 surface is great importance for an atomistic understanding many chemical processes. We present a scanning tunneling microcopy (STM) study molecular either at bridge-bonded vacancies (BBO(V)) or hydroxyls (OH) surface. Using in situ O(2) dosing method, we are able to directly verify exact sites and dynamic O(2). Our experiments provide direct evidence that molecule can intrinsically adsorb both...

A new mechanism for negative differential resistance (NDR) originating from local orbital symmetry matching between an electrode and a molecule in single molecular electronic device is proposed demonstrated by joint experimental theoretical scanning tunneling microscope study of cobalt phthalocyanines (CoPc) on gold substrate. For two different metal tips used, Ni W, NDR occurs only with shows no dependence the geometrical shape tip. Calculations reveal that such behavior result tip Co atom.

We demonstrate the charge state of C60 on a Cu(111) surface can be made optimal, i.e., forming C60(3-) as required for superconductivity in bulk alkali-doped C60, purely through interface reconstruction rather than with foreign dopants. link origin to reconstructed ordered (4x4) 7-atom vacancy holes surface. In contrast, adsorbed unreconstructed receives much smaller amount electrons. Our results illustrate definitive effect that affects electronic properties molecule-electrode contact.

We demonstrate in this joint experimental and theoretical study how one can alter electron transport behavior of a single melamine molecule adsorbed on Cu (100) surface by performing sequence elegantly devised well-controlled molecular chemical processes. It is found that with dehydrogenation reaction, the becomes firmly bonded onto acts as normal conductor controlled elastic tunneling. A current-induced hydrogen tautomerization process results an asymmetric tautomer, which turn leads to...

Two-dimensional transition metal dichalcogenides (TMDs) have been regarded as one of the best nonartificial low-dimensional building blocks for developing spintronic nanodevices. However, lack spin polarization in vicinity Fermi surface and local magnetic moment pristine TMDs has greatly hampered exploitation magnetotransport properties. Herein, a half-metallic structure is successfully developed by simple chemical defect-engineering strategy. Dual native defects decorate titanium...

Superconductivity is mutually exclusive with ferromagnetism, because the ferromagnetic exchange field often destructive to superconducting pairing correlation. Well-designed chemical and physical methods have been devoted realize their coexistence only by structural integrity of inherent ingredients. However, such in freestanding structure nonsuperconducting nonferromagnetic components still remains a great challenge up now. Here, we demonstrate molecule-confined engineering two-dimensional...

Since the discovery of quantum spin Hall (QSH) effect in graphene, searching for two-dimensional (2D) QSH materials with larger bulk gap has been an active field past decade. As cousins elemental graphene-like 2D (Xenes, X refers to group-IV, group-V, or group-VI elements) have particularly interested search state as they share a similar honeycomb lattice graphene. For those Xenes heavier elements, theory predicted extraordinarily large suitable room-temperature applications that...

A first-principles study is performed to explore the electronic and magnetic properties of several 3d transition metal phthalocyanines (including MnPc, FePc, NiPc, CuPc) adsorbed on a Au(111) surface. Our results show that most favorite adsorption site top for MnPc molecule whereas it hcp other molecules. The structures FePc change obviously when they are onto surface, while those NiPc CuPc slightly near Fermi level due weak molecule−surface interactions. By analyzing d orbitals at spatial...

Converting CO${}_{2}$ to useful compounds through the solar photocatalytic reduction has been one of most promising strategies for artificial carbon recycling. The highly relevant substrate conversion could be popular TiO${}_{2}$ surfaces. However, lack accurate measurements energy level alignment that determines on limited our ability control these complicated photocatalysis processes. We report here a systematic study at specific sites rutile...

It has long been under debate whether the electron transport performance of graphene could be enhanced by possible occurrence van Hove singularities in grain boundaries. Here, we provide direct experimental evidence to confirm existence singularity states close Fermi energy certain ordered boundaries using scanning tunneling microscopy. The intrinsic atomic and electronic structures two boundaries, one with alternative pentagon heptagon rings other pair octagon rings, are determined. is...

Abstract The development of next-generation electronics is much dependent on the discovery materials with exceptional surface-state spin and valley properties. Because that, bismuth has attracted a renewed interest in recent years. However, despite extensive studies, intrinsic electronic transport properties Bi surfaces are largely undetermined due to strong interference from bulk. Here we report unambiguous determination Landau levels (111) ultrathin films using scanning tunnelling...

The doping types of graphene sheets are generally tuned by different dopants with either three or five valence electrons. As a five-valence-electrons element, however, nitrogen in have several substitutional geometries. So far, their distinct effects on electronic properties predicted theoretical calculations not been well identified. Here, we demonstrate that the can be N monoelement under proper growth conditions using chemical vapor deposition (CVD), characterized combining scanning...

We report an example that demonstrates the clear interdependence between surface-supported reactions and molecular-adsorption configurations. Two biphenyl-based molecules with two four bromine substituents, i.e., 2,2'-dibromobiphenyl (DBBP) 2,2',6,6'-tetrabromo-1,1'-biphenyl (TBBP), show completely different reaction pathways on a Ag(111) surface, leading to selective formation of dibenzo[e,l]pyrene biphenylene dimer, respectively. By combining low-temperature scanning tunneling microscopy,...

Ultrathin van der Waals (vdW) magnets are heavily pursued for potential applications in developing high-density miniaturized electronic/spintronic devices as well topological physics low-dimensional structures. Despite the rapid advances ultrathin ferromagnetic vdW magnets, antiferromagnetic counterparts, junctions, much less studied owing to difficulties both material fabrication and magnetism characterization. CrTe3 layers have been theoretically proposed be a semiconductor with intrinsic...

We systematically investigated the photocatalytic reaction of methanol on TiO2 (110)-(1 × 1) surface under irradiation with ultraviolet (UV) light performed at various conditions, using scanning tunneling microscopy (STM) jointed temperature-programmed desorption (TPD) techniques. Our STM and TPD results show that is indeed initiated from molecular 5-fold coordinated Ti sites, as commonly ascribed to oxidation by photogenerated holes, reflecting highly photoactive nature methanol. The...

Adsorption of magnetic transition metal atoms on a surface leads to the formation Kondo states at atom/metal interfaces. However, significant influence surrounding environment presents challenges for potential applications. In this work, we realize novel strategy regularize by moving CoPc molecular mold an Au(111) capture dispersed Co adatoms. The symmetric and ordered structures atom-mold complexes, as well strong d

The adsorption and chiral expression of 6-nitrospiropyran (SP6) molecules on a Au(111) surface are studied by scanning tunneling microscopy (STM) in combination with density functional theory (DFT) calculations. Both the chirality orientation each adsorbed SP6 molecule determined. racemic mixture enantiomers forms two-dimensional (2D) domains same close packed positional orders but different internal orientational structures due to random distribution two orientations domain. However, all...