Search results

1

Stark Effect and Scanning Tunneling Spectroscopy of the Ag(111) Surface State

100%

Limot L., Maroutian T., Johansson P., Berndt R.

Acta Physica Polonica A

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2003

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vol. 104

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issue 3-4

185-191

EN

Low-temperature scanning tunneling spectroscopy is used to study the Ag(111) surface state over an unprecedented range of junction resistances. The presence of the tip causes a shift of the surface state towards higher binding energies, increasingly stronger as the resistance decreases. A one-dimensional model calculation reproduces this observation and provides a connection to existing photoemission spectroscopy data. Implications of the effect on STS studies are discussed.

2

STM and STS Investigations of Bi_2Te_3 Surface

100%

Winiarz S., Czajka R., Suto S., Lośtak P., Szuba S., Kasuya A.

Acta Physica Polonica A

|

2003

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vol. 104

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issue 3-4

389-395

EN

We carried out scanning tunneling microscopy/spectroscopy studies of Bi_2Te_3 surface, which, to the best of our knowledge, had not been attempted so far. We got images of surface of the material in many scales from micrometers to nanometers, which showed a layered structure of Bi_2Te_3, with many monoatomic terraces. We found agreement between measured heights and corresponding bulk crystal structure derived from X-ray data. In nanoscale we obtained an atomic resolution. Using scanning tunneling spectroscopy we carried out examination of the electronic structure. We observed different I-V characteristics and contrast on current imaging tunneling spectroscopy maps on non equivalent terraces. The dI/dV (~ density of states) curves referred to those terraces were compared with theoretically calculated by Larson et al. density of states derived from Bi p and Te-1 p orbitals. The analysis of our results allowed us to distinguish bismuth from tellurium planes.

3

Scanning Tunnelling Spectroscopy of Periodic Nickel Nanoparticles

100%

Kamiński M., Susła B., Giersig M., Kandulski M.

Acta Physica Polonica A

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2003

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vol. 104

|

issue 3-4

351-356

EN

Scanning tunneling microscopy/spectroscopy as well as atomic force microscopy were applied to study the non-structural and nanoelectronic properties of periodic nickel nanoparticles deposited on n-silicon substrates. Periodic nickel (Ni) nanoparticles were prepared by using nanosphere lithography and analyzed by scanning tunneling microscopy/spectroscopy and atomic force microscopy. By the evaporation of Ni perfectly ordered nanoparticles were produced and very good correlation between latex mask was observed. Finally, tunneling spectroscopy performed with non-magnetic tip yield information about local electronic properties of nanoscale structures at surface.

4

Fourier Transform Scanning Tunneling Spectroscopy: A New Window on the Electronic Structure of Bi_2Sr_2CaCu_2O_{8+δ}

100%

Davis J.

Acta Physica Polonica A

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2003

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vol. 104

|

issue 3-4

193-204

EN

Scanning tunneling spectroscopy is used to study the dispersive wave vectors of the local-density-of-states modulations in near-optimal Bi_2Sr_2CaCu_2O_{8+δ}. Atomic-resolution energy-resolved spectroscopic images are acquired in a 650Å field of view on the BiO cleave surface of these crystals at 4.2 K. Fourier transforms are used to measure the wave vectors of spatial modulations in the local density of states. At sub-gap energies, up to 16 inequivalent sets of dispersive wave vectors are observed. When analyzed within a model of quasiparticle scattering-induced interference between a characteristic "octet" of states in momentum-space, they yield an estimate of the Fermi-surface location and the energy gap |Δ(k)| in agreement with angle-resolved photoemission spectroscopy. At energies approaching the gap-maximum, the local-density-of-states modulations become intense, commensurate with the crystal, and localized by the apparent nanoscale domains. This may indicate that the lifetimes of the k=(π/a_0,0) quasiparticles are determined by nanoscale disorder scattering.

5

SPM Characterization of Titanium Disilicide Nanostructures Grown on a Ni-Modified Si(100) Substrate

100%

Koczorowski W., Bazarnik M., Czajka R.

Acta Physica Polonica A

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2011

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vol. 120

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issue 3

480-484

EN

The paper presents our recent investigations of the early stage growth of titanium silicides on a modified Si(100) substrate. The substrate was modified by deposition of a minute amount of Ni atoms, and the subsequent flash annealing. This process led to the creation of parallel defect lines on the Si(100) surface. We expected TiSi_2 to form elongated structures on top and/or between the defect lines. Though this idea failed, stable nanostructures were observed and characterized using scanning probe microscopy (scanning tunneling microscopy and atomic force microscopy) methods.

6

A New Generation of Variable Temperature Scanning Probe Microscope for Spectroscopy

100%

Chomiuk P., Uder B., Bettac A., Köble J., Tröppner C.

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vol. 125

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issue 4

1049-1051

EN

In this contribution we present the design and first results of a new generation of variable temperature scanning probe microscope that has been developed to enhance the performance in tunnelling spectroscopy at lower temperatures. Its performance has been proven with imaging and spectroscopy experiments on the well known Si(111), Au(111), and Ag(111) surfaces.

7

Influence of the Interorbital Interference on the Electron Tunneling in Scanning Tunneling Microscopy

80%

Jurczyszyn L.

Acta Physica Polonica A

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2003

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vol. 104

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issue 3-4

217-230

EN

This article presents theoretical study of the influence of the interorbital interference on the electron tunneling in scanning tunneling microscopy. Detailed analysis shows that this kind of interference may modify significantly the tunneling current by the increase or decrease in the current contributions flowing through different orbitals of the surface atoms. This factor might cause the differences between the height and kind of scanning tunneling microscopy corrugation at different metal surfaces. This also might be a source of the unexpectedly high corrugation obtained from scanning tunneling microscopy measurements performed for some metal surfaces, which cannot be explained by the charge distribution along the substrate surface. The effects connected with the interorbital interference will be discussed in the context of the scanning tunneling microscopy simulations performed for Ni_3Al (111) and (001) surfaces.

8

STM-Induced Luminescence for Alkanethiol Films on Au(111) Surface

80%

Nishitani R., Tateishi Y., Arakawa H., Kasuya A., Sumiyama K.

Acta Physica Polonica A

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2003

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vol. 104

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issue 3-4

269-279

EN

STM-induced luminescence spectra for organic molecule adsorbed Au(111) surfaces were studied, and the influence of STM-tip alloy material on the emission spectra was measured. We observed the STM-tip dependent emission spectra of Au(111). The characteristics of the spectra with Pt-Ir alloy(20%) tip are interpreted in terms of the one-mode type and two-mode type depending on the composition rates. We measured the emission spectra for two different types of molecules, decanethiol and octanedithiol, which have different adsorption structures. The emission spectra for the octanedithiol films were compared with the spectra from clean gold films and the decanethiol films. A spectral change of Au(111) due to adsorption of octanedithiol molecules on Au(111) was observed in the spectral range from 700 through 780 nm while not for the adsorption of decanethiol molecules. The spectral change due to adsorption of octanedithiol molecules is compared with the STS measurements.

9

Low Temperature STM/STS, Standard AFM and XPS οf Local MgB_x Phases

80%

Strzelczyk B.

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issue 2

417-419

EN

Low temperature scanning tunneling microscopy/ scanning tunneling spectroscopy, room temperature atomic force microscopy and X-ray photoelectron spectroscopy of the boron ions implanted into the magnesium substrate were performed in order to get information about the local superconducting behavior of thin MgB_{x} film. Results confirm the island superconductivity far from the percolation threshold of the bulk superconducting MgB_2 sample.

10

Spin-Polarized STM Investigation of Magnetic Domain Walls

80%

Kubetzka A., Pietzsch O., Bode M., Ravlić R., Wiesendanger R.

Acta Physica Polonica A

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2003

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vol. 104

|

issue 3-4

259-268

EN

The potential of spin-polarized scanning tunneling microscopy and spectroscopy for the investigation of magnetism at the nanometer scale is demonstrated by focusing on magnetic domain walls. After reviewing different measurement modes it is shown that in addition to wall widths and positions the determination of their exact profiles provides further insight into the samples' magnetic properties.

11

Variable Temperature STM/STS Investigations of Ag Nanoparticles Growth on Semiconductor Surfaces

80%

Suto S., Czajka R., Szuba S., Shiwa A., Winiarz S., Nagashima H., Kato H., Yamada T., Kasuya A.

Acta Physica Polonica A

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2003

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vol. 104

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issue 3-4

289-302

EN

We have investigated the growth of Ag nanoparticles deposited on Si(111), H/Si(111)-(1×1) and Bi_2Te_3 substrates using a variable temperature scanning tunneling microscopy. These substrates are different as regards the model system for cluster and islands growth at the nanometer scale. Ag was evaporated onto the sample mounted at the scanning tunneling microscopy stage in vacuum of 10^{-10} Torr range during evaporation. The substrates were kept at different temperatures: -150˚C, room temperature, and 300˚C during the deposition process. In general, we have observed 3D growth mode up to several ML coverage. The density of clusters and their size were functions of the substrate's temperature during the deposition process - a higher density and a smaller size at -150˚C were in opposition to the 300˚C results - a lower density and a larger size. Low temperature depositions led to continuous layers above 10 ML coverage but the surface was covered by small Ag clusters of 1-2 nm in heights and 2-3 nm in diameters. The log-log graphs of height and projected diameter of Ag clusters revealed different slopes indicating different growth mechanisms at low and high temperatures. We obtained the value of n=0.25±0.02, typical of the so-called droplet model of cluster growth, only at 300˚C. Scanning tunneling spectroscopy measurements revealed clearly different I-V (and dI/dV vs. bias voltage) curves measured above clusters and directly above the substrate. In discussion, we compared our results to theoretically calculated density of states from other papers, finding conformity for partial density of states.

12

Low-Temperature Scanning Tunneling Spectroscopy of Semiconductor Surfaces

80%

Feenstra R., Meyer G., Moresco F., Rieder K.

Acta Physica Polonica A

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2003

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vol. 104

|

issue 3-4

205-216

EN

Low-temperature scanning tunneling spectroscopy measurements on semiconductor surface are described. We consider both surfaces which do not possess surface states within the bulk bandgap, such as GaAs(110), and surfaces which do have states within the gap, such as Ge(111) 2×1 and Ge(111)c(2×8). Band bending in the semiconductor due to the electric field in the vacuum penetrating the semiconductor is found to be a substantial effect in the former case. Transport limitations in the semiconductor give rise to additional voltage drops, which can be observed by making measurements over a wide range of tunnel current magnitudes.

13

STM/STS Investigations of Surface Evolution of Si(111)-(7×7) Induced with Nickel

80%

Gutek J., Szuba S., Czajka R.

Acta Physica Polonica A

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2003

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vol. 104

|

issue 3-4

345-350

EN

By means of scanning tunneling microscopy and spectroscopy we studied the surface evolution of Si(111)-(7×7) induced with nickel followed by annealing at specified temperatures (400, 600, and 800˚C). Nickel evaporation resulted with 0.05 ML and 0.2 ML coverage was carried out at room temperature with the use of solid phase epitaxy. The characteristic phase formations occurred after gradual annealing the sample depending on the amount of deposited material. At very low coverages scanning tunneling microscopy observation showed two types of ring clusters (1×1 -RC and clusters of the √(19)×√(19) reconstruction) accompanied by the Si(111)-(7×7) surface reconstruction. All above-mentioned phases appeared in that order as the annealing temperature increased. Deposition of about 0.2 ML of Ni followed by annealing at 600˚C formed extended regions of 1×1 nickel silicide reconstruction. Very clear, extended regions of √(19)×√(19) reconstruction appeared when annealed to 800˚C. The electronic properties of observed structures have been studied by the scanning tunneling spectroscopy. Spectroscopy curves measured above certain surface formations revealed the presence of the Si rest atom, NiSi, and NiSi_2 local density of electronic states.

14

STM/STS Studies of the Structural Phase Transition in the Growth of Ultra-Thin Bi Films on Si(111)

80%

Sadowski J., Nagao T., Saito M., Oreshkin A., Yaginuma S., Hasegawa S., Ohno T., Sakurai T.

Acta Physica Polonica A

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2003

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vol. 104

|

issue 3-4

381-387

EN

Growth of thin metal films on semiconductors has been always an important subject for extensive experimental and theoretical studies. As the applicability of well-ordered nanostructures in electronic applications depends strongly on their size and distribution, it is necessary to understand the processes that govern the growth of such structures. In this paper we present the results of investigation of the room temperature growth of thin Bi film on Si(111). In our study we clarified that rotationally disordered, pseudo-cubic Bi(012) islands with uniform height of ≈13Å are formed in the initial stage of Bi film growth. With increase in the amount of bismuth on the surface, islands interconnect maintaining however their uniform height. This process is further accompanied by the unique and unexpected structural phase transition of the Bi(012) film into a hexagonal Bi(001) film.

15

Scanning Tunneling Spectroscopy and Luminescent Properties of ZnS:Mn,Cu,Cl Thin Films

80%

Neunert G., Kamiński M., Susła B., Dunaj T., Chimczak E., Bertrandt-Żytkowiak M.

Acta Physica Polonica A

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2003

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vol. 104

|

issue 3-4

357-363

EN

Electrical and luminescent properties of ZnS:Mn,Cu,Cl thin films were investigated. Combined both studies: scanning tunneling microscopy and scanning tunneling spectroscopy were made. The current and differential conductance versus applied voltage were measured for the ZnS:Mn,Cu,Cl thin films. Additionally, the spectral and kinetic properties of the electroluminescent cells based on the ZnS:Mn,Cu,Cl thin films were measured. The maximum of the electroluminescence lies at 586 nm. The electroluminescence was excited by rectangular wave voltage pulses with pulse length from 1μs to 1 ms. It was shown that time dependence of the electroluminescence is well explained assuming energy transfer between monomolecular centres.

16

STM/STS Studies of Self-Organized Growth of Iron Silicide Nanocrystals on Vicinal Si(111) Surface

80%

Wawro A., Suto S., Czajka R., Kasuya A.

Acta Physica Polonica A

|

2003

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vol. 104

|

issue 3-4

303-319

EN

The evolution of iron silicide structure grown by solid state epitaxy on Si(111) vicinal surface was investigated by scanning tunnelling microscopy. The reactions, which occur on the surface, are compared for two various Fe coverages: 0.33 and 2 monolayers. The annealing at 250˚C does not enable substantial recovery of the surface ordering, deteriorated by Fe deposition at room temperature. The onset of 2×2 surface reconstruction is observed upon annealing at 400˚C. A three-dimensional growth tendency of iron silicide crystallites on a bare Si(111) 7×7 surface was found at 700˚C. In the case of 2 monolayer coverage crystallites nucleate along the edges of substrate terraces forming a regular array of nanometer size dots. Basing on atomically resolved spectroscopic effects and statistical considerations, structure of iron silicide nanocrystallites as well as Schottky-like character of the barrier at the interface between metallic crystallite and semiconducting substrate is deduced.

17

The Structure of the (100) Surface of Ag-In-Gd 1/1 Approximant

80%

Hars S., Sharma H., Smerdon J., Yadav T., Tamura R., Shimoda M., McGrath R.

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vol. 126

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issue 2

479-481

EN

Scanning tunneling microscopy is employed to characterise the structure and morphology of the (100) surface of the Ag-In-Gd 1/1 approximant. The surface prepared by the usual method of sputter-annealing produces step-terrace structure. Observed step heights are consistent with the lattice constant of the bulk. Scanning tunneling microscopy on terraces reveals cluster-like protrusions arranged with a square unit cell as expected from the bulk. It has not been possible to assign the terraces to the specific bulk planes because of lack of atomic resolution on terraces.

18

Study of Ultrathin In-Ag Layers οn Tungsten by Means of Surface Spectroscopy Techniques

80%

Bukaluk A., Trzcinski M., Okulewicz K.

Acta Physica Polonica A

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2008

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vol. 114

|

issue S

S-17-S-28

EN

Auger electron spectroscopy, X-ray photoelectron spectroscopy, ultraviolet photoelectron spectroscopy, scanning tunnelling microscopy, low energy electron diffraction, and thermodesorption methods were used to investigate the process of growth of ultrathin In films and formation of In-Ag surface alloys on tungsten substrate. Several indium layers, having coverage ranging from 0.2 to 0.8 ML were deposited on tungsten substrate in room temperature. It was found that at the lowest coverages (Θ= 0.1-0.3 ML) indium atoms form (3×1) structure, characterized by very sharp low energy electron diffraction patterns. With increasing Θ they tend to form densely packed islands interpreted as slightly distorted In(111) monolayers. Surface diffusion of In onto the tungsten surface was studied by using ESCA imaging property of SCIENTA ESCA200 instrument. Measuring the photoelectron intensity as a function of two spatial coordinates and the energy, we observed movement of In atoms on the tungsten surface. On the basis of the change of surface coverage with distance surface the diffusion coefficient was evaluated at the temperature range of 400-700 K. Intermixing of ultrathin films of indium and silver, after their surface diffusion from the sample edges to the centre of the tungsten surface, were observed by using X-ray photoelectron spectroscopy, ultraviolet photoelectron spectroscopy and the Auger electron spectroscopy methods. Intermixing was controlled by means of photoemission spectra from the valence states and the In 4d level, as well as by X-ray photoelectron spectroscopy studies of indium and silver core levels excited by Al K_α source.

19

The Study of Electron Properties of Carbon Nanotubes Deposited on Highly Orientated Pyrolytical Graphite Using Scanning Probe Spectroscopy

80%

Kamiński M., Wróblewski M., Cęgiel M., Susła B.

Acta Physica Polonica A

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2007

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vol. 111

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issue 5

661-669

EN

In this paper we present experimental investigations of carbon nanotubes deposited on highly orientated pyrolytical graphite using scanning tunneling microscopy and scanning tunneling spectroscopy. The aforementioned methods apart from detailed topographic data provided us with information about local density of state. We also show the I-V and dI/dV characteristics, which display the metallic and semiconducting characters of investigated carbon nanotubes. All measurements were taken in the air and at room temperature.

20

Dependence of STM Images οn Bias Polarity for Sm Layers οn Mo(110) and Mo(211) Surfaces

80%

Kuchowicz M., Szukiewicz R., Grodzińska D.

Acta Physica Polonica A

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2008

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vol. 114

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issue S

S-59-S-69

EN

Thin Sm layers adsorbed on Mo(110) and (211) surfaces were studied with scanning tunneling microscope. It was found that obtained images of these adsorption systems significantly depend on the polarity of the scanning tunneling microscope bias voltage. This dependence is more pronounced for the Sm on Mo(110) than on Mo(211). For Sm/Mo(110), at low Sm coverages the change of bias polarity results in significant difference in the measured height of the adsorbed Sm layer, while the heights of substrate terraces remain the same for both signs of the applied bias voltage. In the coverage range 0.65<θ<1, scanning tunneling microscope images, obtained with negative bias, show the gaps in Sm layers, which are invisible for positive bias.

Refine search results

Stark Effect and Scanning Tunneling Spectroscopy of the Ag(111) Surface State

STM and STS Investigations of Bi_2Te_3 Surface

Scanning Tunnelling Spectroscopy of Periodic Nickel Nanoparticles

Fourier Transform Scanning Tunneling Spectroscopy: A New Window on the Electronic Structure of Bi_2Sr_2CaCu_2O_{8+δ}

SPM Characterization of Titanium Disilicide Nanostructures Grown on a Ni-Modified Si(100) Substrate

A New Generation of Variable Temperature Scanning Probe Microscope for Spectroscopy

Influence of the Interorbital Interference on the Electron Tunneling in Scanning Tunneling Microscopy

STM-Induced Luminescence for Alkanethiol Films on Au(111) Surface

Low Temperature STM/STS, Standard AFM and XPS οf Local MgB_x Phases

Spin-Polarized STM Investigation of Magnetic Domain Walls

Variable Temperature STM/STS Investigations of Ag Nanoparticles Growth on Semiconductor Surfaces

Low-Temperature Scanning Tunneling Spectroscopy of Semiconductor Surfaces

STM/STS Investigations of Surface Evolution of Si(111)-(7×7) Induced with Nickel

STM/STS Studies of the Structural Phase Transition in the Growth of Ultra-Thin Bi Films on Si(111)

Scanning Tunneling Spectroscopy and Luminescent Properties of ZnS:Mn,Cu,Cl Thin Films

STM/STS Studies of Self-Organized Growth of Iron Silicide Nanocrystals on Vicinal Si(111) Surface

The Structure of the (100) Surface of Ag-In-Gd 1/1 Approximant

Study of Ultrathin In-Ag Layers οn Tungsten by Means of Surface Spectroscopy Techniques

The Study of Electron Properties of Carbon Nanotubes Deposited on Highly Orientated Pyrolytical Graphite Using Scanning Probe Spectroscopy

Dependence of STM Images οn Bias Polarity for Sm Layers οn Mo(110) and Mo(211) Surfaces