Synthesis of MOS2 Phase in the Near Surface Region of Al2O3 and ZrO2 by Ion Implantation

1989 ◽  
Vol 157 ◽  
Author(s):  
A.K. Rai ◽  
R.S. Bhattacharya ◽  
S.C. Rung ◽  
D. Patrizio
Keyword(s):  
Electron Microscopy ◽  
Electron Spectroscopy ◽  
Auger Electron ◽  
Surface Region ◽  
Furnace Annealing ◽  
Near Surface ◽  
Depth Profiles ◽  
Annealing Conditions ◽  
Transmission Electron ◽  
Experimental Findings

ABSTRACTAl2O3 and ZrO2 substrates were coimplanted with 175 keV Mo+ and 74 keV S+ at doses of 1×10 cm−2 and 2×1017 cm−2 respectively. The energies of Mo+ and S+ ions were chosen to provide a nearly overlapping depth profiles in both substrates. Rutherford backscattering (RBS), Auger electron spectroscopy (AES) and transmission electron microscopy (TEM) techniques were used for characterization. The as implanted surface of Al2O3 became amorphous while as implanted ZrO2 surface remained crystalline. The MoS2 phase was observed in the as implanted ZrO2. The MoS2 phase was observed in the implanted region of Al2O3 and ZrO2 after furnace annealing at 700°C. Thermodynamic calculations were performed to predict the equilibrium binary phase formed in Al2O3 and ZrO2 under the present implant and annealing conditions. The predictions agree with the experimental findings.

Auger electron spectroscopy analysis of SiC-whisker surfaces and SiC-whisker/alumina interfaces

1995 ◽  
Vol 10 (4) ◽  
pp. 1016-1023 ◽  
Author(s):  
D.N. Braski ◽  
K.B. Alexander
Keyword(s):  
Auger Electron Spectroscopy ◽  
Electron Spectroscopy ◽  
Auger Electron ◽  
Surface Composition ◽  
Surface Region ◽  
Interface Composition ◽  
Near Surface ◽  
Transmission Electron ◽  
Sic Whiskers ◽  
Alumina Composites

Auger Electron Spectroscopy (AES) has been used to examine as-received and oxidized silicon carbide whiskers and their respective whisker/matrix interfaces after fabrication into SiC-whisker-reinforced alumina composites. As-received whisker surfaces exhibited a 2–3 nm-thick near-surface region that was C-rich. Oxygen was detected at the outer surface, but diminished to near zero within 25 nm of the surface. Oxidized whiskers had 60 nm-thick SiO2 surface layers, which was in agreement with the transmission electron microscopy observations. The whisker/matrix interfaces in both composites consisted of thin (<0.5 nm) layers of a C-Si-O noncrystalline material. The thick SiO2 layers on the oxidized whiskers were ejected from the interfaces during hot-pressing. It was concluded that (i) the higher toughness of the composite fabricated with as-received SiC whiskers may be related to the higher C and lower O in its SiCw/Al2O3 interfaces, and (ii) interface composition cannot be reliably predicted using the surface composition of free whiskers prior to fabrication.

Nanoscale Mechanical Properties of In-Situ Tribofilms Generated from ZDDP and F-ZDDP with and without Antioxidants

2007 ◽  
Vol 7 (12) ◽  
pp. 4378-4390 ◽  
Author(s):  
Anuradha Somayaji ◽  
Ramoun Mourhatch ◽  
Pranesh B. Aswath
Keyword(s):  
Electron Microscopy ◽  
Wear Debris ◽  
Surface Region ◽  
Nucleation And Growth ◽  
Near Surface ◽  
Transmission Electron ◽  
Dialkyl Dithiophosphates ◽  
Wear Tests ◽  
Diphenyl Amine

Tribofilms with thickness ranging from 100–200 nm were developed in-situ during wear tests using a zinc dialkyl dithiophosphates (ZDDP) and fluorinated ZDDP (F-ZDDP). The influence of the antioxidant alkylated diphenyl amine on the formation and properties of these tribofilm is examined. Results indicate that the thickness of the tribofilms formed when F-ZDDP is used is always thicker than the tribofilm formed with ZDDP. In addition, in the presence of antioxidants the tribofilm thickness is increased. The hardness of these tribofilms in the absence of the antioxidants is significantly higher at the near surface region (0–30 nm) when compared to the films formed in the presence of antioxidant. Nanoscratch tests conducted to examine the abrasion resistance of the tribofilms also indicate that the tribofilms formed by F-ZDDP are more resistant to scratch compared to films formed by ZDDP. In the presence of antioxidant, tribofilms formed by F-ZDDP are significantly thicker while both films behave in a similar fashion in nanoscratch tests. Transmission electron microscopy of the wear debris formed during the tests were examined and results indicate the nucleation and growth of nanoparticles of Fe3O4 with an approximate size of 5–10 nm embedded within an otherwise amorphous tribofilm.

Auger Electron Spectroscopy and Its Application to Nanotechnology

2011 ◽  
Vol 19 (2) ◽  
pp. 12-15 ◽  
Author(s):  
S. N. Raman ◽  
D. F. Paul ◽  
J. S. Hammond ◽  
K. D. Bomben
Keyword(s):  
Electron Microscopy ◽  
Auger Electron Spectroscopy ◽  
Electron Spectroscopy ◽  
Auger Electron ◽  
Imaging Techniques ◽  
Chemical Characterization ◽  
Depth Resolution ◽  
Surface Modifications ◽  
Transmission Electron ◽  
Nanoscale Characterization

Over the past decade, the field of nanotechnology has expanded, and the most heavily used nanoscale characterization/imaging techniques have been scanning probe microscopy (SPM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Although these high-resolution imaging techniques help visualize nanostructures, it is essential to understand the chemical nature of these materials and their growth mechanisms. Surface modifications in the first few nanometers can alter the bulk properties of these nanostructures, and conventional characterization techniques, including energy dispersive spectroscopy (EDS) and electron energy loss spectroscopy (EELS) associated with SEM and TEM are not suited to detecting these surface modifications except in special, favorable specimens. A modern state-of-the-art scanning Auger electron spectroscopy (AES) instrument provides valuable elemental and chemical characterization of nanostructures with a lateral spatial resolution better than 10 nm and a depth resolution of a few nm. In this article we review the technique of scanning AES and highlight its unique analytical capabilities in the areas of nanotechnology, metallurgy, and semiconductors.

The Distribution of Phosphorus in Romano-British Ironwork

1990 ◽  
Vol 185 ◽  
Author(s):  
Alain E. Kaloyeros ◽  
Robert M. Ehrenreich
Keyword(s):  
Electron Microscopy ◽  
Electron Spectroscopy ◽  
Auger Electron ◽  
Materials Analysis ◽  
X Ray ◽  
Transmission Electron ◽  
Depth Study ◽  
Iron Artifacts ◽  
And Performance ◽  
Secondary Ion

AbstractPhosphorus is found to be a common impurity in many of the iron tools and weapons produced during the pre-Roman and Roman Iron Ages of Britain (600 BC - 300 AD). The effects of this impurity on the properties and performance of antiquarian materials is not well understood, however. This paper presents the initial findings of an in-depth study of the distribution, chemistry, and effects of phosphorus in Romano-British ironwork. For this purpose, two Romano-British iron artifacts from the site of Ircheoter, Northamptonshire, were examined using powerful techniques for archeological materials analysis that include electron microprobe, secondary ion mass spectroscopy (SIMS), transmission electron microscopy (TEM) with energydispersive x-ray spectroscopy capabilities (EDXS), and Auger electron spectroscopy (AES). It was found that phosphorous was indeed present in the artifacts. The phosphorus atoms were predominantly segregated at grain boundaries and thus should have led to a lowering of grain boundary cohesion and a degradation in the performance of the tools.

Copper(I) Halide Nanoparticle-dispersed Glasses Prepared by Copper Staining

2005 ◽  
Vol 20 (9) ◽  
pp. 2480-2485 ◽  
Author(s):  
Kohei Kadono ◽  
Tatsuya Suetsugu ◽  
Takeshi Ohtani ◽  
Toshihiko Einishi ◽  
Takashi Tarumi ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Heat Treatment ◽  
Surface Region ◽  
Borosilicate Glasses ◽  
X Ray Diffraction ◽  
X Ray ◽  
Depth Profiles ◽  
Transmission Electron ◽  
Heat Treated ◽  
Glass Heat

Copper(I) chloride and bromide nanoparticle-dispersed glasses were prepared by means of a conventional copper staining. The staining was performed by the following process: copper stain was applied on the surfaces of Cl−- or Br−-ion-containing borosilicate glasses, and the glasses were heat-treated at 510 °C for various times. Typical exciton bands observed in the absorption spectra of the glasses after the heat treatment indicated that CuCl and CuBr particles were formed in the surface region of the glasses. The average sizes of the CuCl and CuBr particles in the glasses heat-treated for 48 h were estimated at 4.8 and 2.7 nm, respectively. The nanoparticles were also characterized by x-ray diffraction and transmission electron microscopy. Depth profiles of Cu and CuBr concentration in the glass heat-treated for 48 h were measured. Copper decreased in concentration monotonously with depth, reaching up to 60 μm, while the CuBr concentration had a maximum at about 25 μm in depth.

Microstructure Analysis of Thermally Stable Ohmic Contact to Both n and p+-GaAs

1992 ◽  
Vol 281 ◽  
Author(s):  
W. Y. Han ◽  
H. S. Lee ◽  
Y. Lu ◽  
M. W. Cole ◽  
L. M. Casas ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Ohmic Contact ◽  
Auger Electron ◽  
Specific Contact Resistance ◽  
Thermally Stable ◽  
Depth Profiles ◽  
Transmission Electron ◽  
Specific Contact ◽  
Electron Spectrometry

ABSTRACTA thermally stable Pd/Ge/Ti/Pt/ ohmic contact with low specific contact resistance was formed on both n and p+-GaAs. The lowest specific contact resistances were 4.7×10−7 and 6.4×10−7 Ω.cm2 for the n and p+-GaAs, respectively, when the n-GaAs was doped with Si to 2×1018cm−3, and the p+-GaAs was doped with carbon to 5×1019 cm−3. Interfacial reactions and element diffusions of the contacts were investigated by using transmission electron microscopy, Auger electron spectrometry with depth profiles. All the contacts were thermally stable at 300 °C for 20 hours, and it appeared that the p-contacts were more stable than the n-contacts.

Mechanical properties and microstructures of metal/ceramic microlaminates: Part I. Nb/MoSi2 systems

1992 ◽  
Vol 7 (10) ◽  
pp. 2765-2773 ◽  
Author(s):  
T.C. Chou ◽  
T.G. Nieh ◽  
T.Y. Tsui ◽  
G.M. Pharr ◽  
W.C. Oliver
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Transmission Electron Microscopy ◽  
Electron Spectroscopy ◽  
Auger Electron ◽  
Elastic Moduli ◽  
Chemical Interaction ◽  
Transmission Electron ◽  
Metal Ceramic ◽  
Equal Thickness

Artificial multilayers, or microlaminates, composed of alternating layers of Nb and MoSi2 of equal thickness were synthesized by d.c., magnetron sputtering. Four different modulation wavelengths, λ, were studied: 7, 11, 20, and 100 nm. The compositions, periodicities, and microstructures of the microlaminates were characterized by Auger electron spectroscopy and transmission electron microscopy. Structural characterization revealed that the as-deposited Nb layers are polycrystalline, while the MoSi2 layers are amorphous. The hardnesses and elastic moduli of the films were measured using nanoindentation techniques. Neither a supermodulus nor a superhardness effect could be identified in the range of wavelengths investigated; for each of the microlaminates, both the hardness and modulus were found to fall between the bounds set by the properties of the monolithic Nb and MoSi2 films. Nevertheless, a modest but a measurable increase in both hardness and modulus with decreasing wavelength was observed, thus indicating that behavior cannot be entirely described by a simple rule-of-mixtures. The hardness was found to vary linearly with Δ−1/2 in a manner similar to the Hall–Petch relationship. Annealing the microlaminates at 800 °C for 90 min produces significant increases in hardness and modulus due to chemical interaction of the layers.

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