Single particle excitations and electronic structure of ferromagnets in the near-surface region

Abstract. The work shows the possibility of using electroluminescence to study the structures of Si-Ta2O5 and Si-SiO2-Ta2O5 and to obtain the information about the electronic structure of the Ta2O5 layer and the properties of the SiO2-Ta2O5 boundary. A model of the electronic structure of the Ta2O5 layer obtained by molecular layering (atomic layer deposition) is proposed to explain the type of spectral distribution of luminescence regardless of the method of its excitation. It is shown that the formation of a Ta2O5 layer on the surface of thermally oxidized silicon is accompanied by transformation of the near-surface region of SiO2 and quenching of the luminescence band in the spectral region of 650 nm.

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DEPTH-RESOLVED SOFT X-RAY EMISSION SPECTROSCOPY OF Si-BASED MATERIALS

Surface Review and Letters ◽

10.1142/s0218625x02002464 ◽

2002 ◽

Vol 09 (01) ◽

pp. 461-467 ◽

Cited By ~ 14

Author(s):

A. V. ZIMINA ◽

A. S. SHULAKOV ◽

S. EISEBITT ◽

W. EBERHARDT

Keyword(s):

Electronic Structure ◽

Depth Resolution ◽

Surface Region ◽

Primary Electron ◽

Depth Information ◽

Near Surface ◽

X Ray ◽

Chemical Phase ◽

Information Depth ◽

Postimplantation Annealing

We discuss a soft X-ray emission (SXE) valence band (VB) spectroscopy method for the study of the electronic structure and chemical phase composition of solids in a near-surface region with depth resolution. The depth information is obtained by variation of the energy of the incident electron beam used to excite the SXE spectra. As the information depth can be varied from about 1 nm to 1 μm in silicon, this method is suitable for the investigation of materials of modern micro- and nanoelectronics. VB → core level (Si 2p or Al 2p) transitions in Si-based materials are used to demonstrate the technique. It was found that the contribution of the signal from the near-surface region (< 1.5 nm) can be substantial (up to 50%) when the primary electron energy does not exceed the Si L 2,3 threshold by more than 150 eV. The technique is applied to Al impurities in a Si matrix, produced by ion implantation. The electronic structure at the Al sites and depth distribution of the Al impurity change markedly after postimplantation annealing. The observed electronic structure after annealing is in agreement with electronic structure calculations for substitutional Al impurities in a crystalline Si lattice.

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Specific features of the electronic structure of fluorinated multiwalled carbon nanotubes in the near-surface region

Physics of the Solid State ◽

10.1134/s1063783409090327 ◽

2009 ◽

Vol 51 (9) ◽

pp. 1961-1971 ◽

Cited By ~ 2

Author(s):

M. M. Brzhezinskaya ◽

N. A. Vinogradov ◽

V. E. Muradyan ◽

Yu. M. Shul’ga ◽

R. Püttner ◽

...

Keyword(s):

Carbon Nanotubes ◽

Electronic Structure ◽

Multiwalled Carbon Nanotubes ◽

Surface Region ◽

Multiwalled Carbon ◽

Near Surface

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Electronic structure of thermally oxidized tungsten

Journal of Physics Conference Series ◽

10.1088/1742-6596/2103/1/012234 ◽

2021 ◽

Vol 2103 (1) ◽

pp. 012234

Author(s):

S N Timoshnev ◽

P A Dementev ◽

E V Dementeva ◽

M N Lapushkin ◽

D A Smirnov

Keyword(s):

Electronic Structure ◽

Thermal Oxidation ◽

Valence Band ◽

Oxidation State ◽

Oxygen Pressure ◽

Organic Molecules ◽

Surface Region ◽

Tungsten Oxides ◽

Near Surface ◽

Tungsten Foil

Abstract The electronic structure of thermally oxidized tungsten used as an emitter in thermal ionization of organic molecules is studied. Tungsten foil was thermally oxidized at oxygen pressure 1 Torr and temperature 950 K. The photoemission spectra from the valence band and O 2s and W 4f core levels are studied under synchrotron excitation with the photon energies 100 ÷ 600 eV. It is shown that thermal oxidation of tungsten leads to the formation in the W near-surface region various tungsten oxides with an oxidation state from 6+ to 4+. In this case, mainly tungsten oxides with an oxidation state of 6+ are formed on the surface, the proportion of which gradually decreases with distance from the surface with an increase in tungsten oxides with an oxidation state of 4+.

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Preparation of cross-sectional samples for near-surface TEM studies

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010012669x ◽

1987 ◽

Vol 45 ◽

pp. 380-381

Author(s):

R.C. Dickenson ◽

K.R. Lawless

Keyword(s):

Standard Sample ◽

Surface Region ◽

Specimen Preparation ◽

Thick Sheet ◽

Drill Bit ◽

Sample Holder ◽

Metal Interface ◽

Cross Sectional ◽

Near Surface ◽

Cold Worked

In thermal oxidation studies, the structure of the oxide-metal interface and the near-surface region is of great importance. A technique has been developed for constructing cross-sectional samples of oxidized aluminum alloys, which reveal these regions. The specimen preparation procedure is as follows: An ultra-sonic drill is used to cut a 3mm diameter disc from a 1.0mm thick sheet of the material. The disc is mounted on a brass block with low-melting wax, and a 1.0mm hole is drilled in the disc using a #60 drill bit. The drill is positioned so that the edge of the hole is tangent to the center of the disc (Fig. 1) . The disc is removed from the mount and cleaned with acetone to remove any traces of wax. To remove the cold-worked layer from the surface of the hole, the disc is placed in a standard sample holder for a Tenupol electropolisher so that the hole is in the center of the area to be polished.

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The Effects of Ion Implantation on the Surface Features of Inconel 600

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100118333 ◽

1985 ◽

Vol 43 ◽

pp. 288-289

Author(s):

John D. Rubio

Keyword(s):

Grain Boundary ◽

Ion Implantation ◽

Nuclear Power ◽

Power Plants ◽

Surface Region ◽

Selective Dissolution ◽

Boundary Region ◽

Near Surface ◽

Inconel 600 ◽

Steam Generator Tubing

The degradation of steam generator tubing at nuclear power plants has become an important problem for the electric utilities generating nuclear power. The material used for the tubing, Inconel 600, has been found to be succeptible to intergranular attack (IGA). IGA is the selective dissolution of material along its grain boundaries. The author believes that the sensitivity of Inconel 600 to IGA can be minimized by homogenizing the near-surface region using ion implantation. The collisions between the implanted ions and the atoms in the grain boundary region would displace the atoms and thus effectively smear the grain boundary.To determine the validity of this hypothesis, an Inconel 600 sample was implanted with 100kV N2+ ions to a dose of 1x1016 ions/cm2 and electrolytically etched in a 5% Nital solution at 5V for 20 seconds. The etched sample was then examined using a JEOL JSM25S scanning electron microscope.

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Microstructural changes of Aluminum Nitride after laser irradiation and electroless copper deposition

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100170918 ◽

1994 ◽

Vol 52 ◽

pp. 636-637

Author(s):

S. Cao ◽

A. J. Pedraza ◽

L. F. Allard

Keyword(s):

Aluminum Nitride ◽

Laser Irradiation ◽

Electroless Deposition ◽

Thermal Evaporation ◽

Surface Region ◽

Near Surface ◽

Laser Patterning ◽

Electroless Copper ◽

Excimer Laser Irradiation ◽

Laser Effect

Excimer-laser irradiation strongly modifies the near-surface region of aluminum nitride (AIN) substrates. The surface acquires a distinctive metallic appearance and the electrical resistivity of the near-surface region drastically decreases after laser irradiation. These results indicate that Al forms at the surface as a result of the decomposition of the Al (which has been confirmed by XPS). A computer model that incorporates two opposing phenomena, decomposition of the AIN that leaves a metallic Al film on the surface, and thermal evaporation of the Al, demonstrated that saturation of film thickness and, hence, of electrical resistance is reached when the rate of Al evaporation equals the rate of AIN decomposition. In an electroless copper bath, Cu is only deposited in laser-irradiated areas. This laser effect has been designated laser activation for electroless deposition. Laser activation eliminates the need of seeding for nucleating the initial layer of electroless Cu. Thus, AIN metallization can be achieved by laser patterning followed by electroless deposition.

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