Structure of Amorphous A12O3 Produced by Ion Implantation

1989 ◽  
Vol 157 ◽  
Author(s):  
C. J. Mchargue ◽  
P. S. Sklad ◽  
P. Angelini ◽  
C. W. White ◽  
J. C. Mccallum ◽  
...  
Keyword(s):  
Ion Implantation ◽  
Short Range ◽  
Room Temperature ◽  
Short Range Order ◽  
Ion Beam ◽  
Amorphous State ◽  
Electronic Charge ◽  
Stoichiometric Ratio ◽  
Chemical Effects ◽  
Critical Composition

ABSTRACTThe amorphous state can be produced in α-Al2O3 by ion beam induced displacements at 77 K or by displacements combined with chemical effects at room temperature. Progress toward understanding the amorphization process has been made from studies of the short-range order, electronic charge on implanted species, and the critical composition for amorphization. Results are presented for implantation of Al + O in the stoichiometric ratio, zirconium, iron, and tin.

scholarly journals X-ray diffraction study of structure of CaO-Al2O3-SiO2 ternary compounds in molten and crystalline states

2020 ◽  
Vol 56 (2) ◽  
pp. 269-277
Author(s):  
V.E. Sokol’skii ◽  
D.V. Pruttskov ◽  
O.M. Yakovenko ◽  
V.P. Kazimirov ◽  
O.S. Roik ◽  
...  
Keyword(s):  
Short Range ◽  
Room Temperature ◽  
Short Range Order ◽  
Structural Parameters ◽  
Range Order ◽  
Reverse Monte Carlo ◽  
X Ray Diffraction ◽  
Xrd Pattern ◽  
X Ray ◽  
Ternary Compounds

Anorthite and gehlenite crystalline structure and short-range order of anorthite melt have been studied by X-ray diffraction in the temperature range from room temperature up to ~ 1923 K. The corresponding anorthite and gehlenite phases were identified as well as amorphous component for anorthite samples having identical shape to XRD pattern of the anorthite melt. The structure factor and the radial distribution function of atoms of the anorthite melt were calculated from the X-ray high-temperature experimental data. The partial structural parameters of the short-range order of the melt were reconstructed using Reverse Monte Carlo simulations.

Recent Advances in The Application of Focused Ion Beams

1985 ◽  
Vol 45 ◽  
Author(s):  
Kenji Gamo ◽  
Susumu Namba
Keyword(s):  
Ion Implantation ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Ion Beams ◽  
Focused Ion Beams ◽  
Ion Beam Modification ◽  
Chemical Effects ◽  
Recent Advances ◽  
Maskless Patterning

Recent advances of focused ion beam systems and their applications are presented. The applications include maskless ion implantation and various maskless patterning techniques which make use of ion induced chemical effects. These are ion beam assisted etching, deposition and ion beam modification techniques and are promising to improve patterning speed and extend applications of focused ion beams.

scholarly journals Structure Factors of Liquid Cu-Pb Alloys by Neutron Diffraction

1980 ◽  
Vol 35 (11) ◽  
pp. 1178-1181 ◽  
Author(s):  
Peter Lamparter ◽  
Siegfried Steeb
Keyword(s):  
Neutron Diffraction ◽  
Order Parameter ◽  
Short Range ◽  
Short Range Order ◽  
Marked Effect ◽  
Pair Correlation ◽  
Nearest Neighbour ◽  
Critical Composition ◽  
Structure Factors ◽  
Angle Scattering

Abstract By means of neutron diffraction the structure factors and pair correlation functions of five Cu-Pb alloys, Cu, and Pb in the liquid state have been determined. The nearest neighbour distances have been obtained. The marked effect of small angle scattering with the melt with critical composition (65 at % Cu) is a proof for microsegregation tendency. By comparison with a segregation model for the structure factor the short range order parameter has been derived for melts with 65 and 35 at % Cu, respectively.

The Structure of Fe on Al(001)

1998 ◽  
Vol 05 (05) ◽  
pp. 1007-1014 ◽  
Author(s):  
M. Hochstrasser ◽  
A. Atrei ◽  
B. Bolliger ◽  
R. Eismann ◽  
M. Erbudak ◽  
...  
Keyword(s):  
Short Range ◽  
Room Temperature ◽  
Short Range Order ◽  
Magnetic Ordering ◽  
The Body ◽  
Range Order ◽  
Body Centered Cubic ◽  
Plane Component ◽  
Surface Magnetization ◽  
Cubic Structure

The structure of Fe deposited on Al(001) at room temperature has been investigated during growth. It is found that even less than 1 monolayer (ML) of Fe destroys the atomic order at the surface due to the interdiffusion of Fe and Al. After deposition of 3±0.5 ML, short-range order at the surface is restored due to islands which locally have the body-centered cubic structure and are aligned in registry with the Al matrix. These islands coalesce during further Fe deposition, and produce poor long-range order at an Fe dose of 5±0.5 ML. At this coverage, magnetic ordering is found perpendicular to the surface. The in-plane component of the surface magnetization is detected above 8±0.5 ML.

Optical transitions in the modulated reflectivity spectrum of ion-implanted GaAs

1979 ◽  
Vol 57 (6) ◽  
pp. 917-919
Author(s):  
U. Giorgianni ◽  
V. Grasso ◽  
G. Mondio ◽  
P. Perillo ◽  
G. Saitta
Keyword(s):  
Absorption Coefficient ◽  
Energy Range ◽  
Photon Energy ◽  
Short Range ◽  
Room Temperature ◽  
Short Range Order ◽  
Optical Transitions ◽  
Optical Behaviour ◽  
Reflectivity Spectrum ◽  
Ion Implanted

The wavelength modulated reflectivity spectrum of ion-implanted GaAs in the photon energy range 1.5–7.0 eV is reported. The specimens were obtained by 400 keV Te implantation at room temperature. Strong differences were found with respect to the optical behaviour of flash-evaporated films and crystalline samples. The Penn theory for materials with tetrahedral short-range order was applied and the absorption coefficient of ion-implanted GaAs is also reported.

scholarly journals Modification of diazoquinone-novolac photoresist films by boron ion implantation

2020 ◽  
pp. 62-69
Author(s):  
Dmitrii I. Brinkevich ◽  
Uladislau S. Prasalovich ◽  
Yury N. Yankouski
Keyword(s):  
Ion Implantation ◽  
Room Temperature ◽  
Ion Beam ◽  
Plane Deformation ◽  
Dose Range ◽  
Current Mode ◽  
Total Reflection ◽  
Attenuated Total Reflection ◽  
Positive Photoresist ◽  
Stretching Vibrations

Diazoquinone-novolac photoresist films implanted with B+ ions were studied by the method of attenuated total reflection (ATR). Films of positive photoresist FP9120 with a thickness h of 1.0 and 2.5 mm were deposited by centrifuging on p-type silicon plates with (111) orientation. Implantation with 60 keV B+ions in the dose range of 1015–1016 cm–2 in the constant ion current mode (current density 4 mA/cm2 ) was carried out at room temperature in a residual vacuum not worse than 10–5 Pa using the «Vesuvius-6» ion beam accelerator. The attenuated total reflection spectra were recorded in the range 400 – 4000 cm–1 by ALPHA spectrophotometer (Bruker Optik GmbH, Germany) at room temperature. It was shown that ion implantation leads to intensive transformation of the photoresist beyond the range of ions, which is characterized by the appearance in the spectrum of intense bands with peaks at 2151 and 2115 cm–1, due to stretching vibrations of double cumulative bonds, in particular С——С——О. In the implanted samples, a shift to the low-energy region of the maxima of the stretching vibrations of C—H bonds, plane deformation vibrations of O—H bonds and pulsating vibrations of the carbon skeleton of aromatic rings as well as the redistribution of intensities between closely spaced maxima, were observed.

Formation of AlGaAs by ion beam mixing of Al films on GaAs

1990 ◽  
Vol 48 (4) ◽  
pp. 690-691
Author(s):  
R.S. Deol ◽  
E.A. Kamil ◽  
K.P. Homewood ◽  
T. Kobayashi
Keyword(s):  
Ion Implantation ◽  
Room Temperature ◽  
Ion Beam ◽  
Chamber Pressure ◽  
Pure Aluminium ◽  
Material Synthesis ◽  
Ion Beam Mixing ◽  
Implantation Energy ◽  
Gaas Substrates ◽  
Heated Filament

There is considerable interest in the use of ion implantation for material synthesis. The synthesis of AlGaAs by dual implants of As+ and Al+ into GaAs followed by rapid thermal annealing (RTA) has been reported recently. In this paper results relating to the formation of AlxGa1-xAs by depositing thin Al films on GaAs substrates and irradiating with arsenic ions followed by RTA are presented.Aluminium layers of 580Å or 650Å in thickness were deposited onto liquid encapsulated Czochralski (LEC) grown samples of semi-insulating <100> GaAs. The deposition was done using pure aluminium on a heated filament at a chamber pressure of ∽10−6 Torr with the thickness being measured using a talystep. Subsquently As+ implants were performed at room temperature using an energy of 150, 200 or 300 keV and a dose of 3x1016 or 1x1017 cm−2. The implantation energy was selected to ensure that the projected depth exceeded the thickness of the Al overlayer employed.

scholarly journals Thermodynamic properties of dilute Co-Fe solid solutions studied by 57Fe Mössbauer spectroscopy

Nukleonika ◽  
2017 ◽  
Vol 62 (2) ◽  
pp. 109-115 ◽  
Author(s):  
Robert Konieczny ◽  
Rafał Idczak
Keyword(s):  
Mössbauer Spectroscopy ◽  
Short Range ◽  
Room Temperature ◽  
Short Range Order ◽  
Enthalpy Of Solution ◽  
Mossbauer Spectroscopy ◽  
Enthalpy Of Mixing ◽  
Mößbauer Spectroscopy ◽  
Transmission Mössbauer Spectroscopy

Abstract The Co1-xFex alloys where x ranges from 0.01 to 0.06 were measured at room temperature using transmission Mössbauer spectroscopy (TMS). The analysis of the obtained data allowed the determination of the short-range order (SRO), the binding energy Eb between two iron atoms in the studied materials using the extended Hrynkiewicz-Królas idea and the enthalpy of solution HCo-Fe of Fe in Co. The results showed that the Fe atoms dissolved in a Co matrix interact repulsively and the estimated value of HCo-Fe = -0.166(33) eV/atom. Finally, values of the enthalpy of solution were used to predict the enthalpy of mixing for the Co-Fe system. These findings were compared with corresponding data given in the literature, which were derived from calorimetric experiments and from the cellular atomic model of alloys described by Miedema.

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