Evolution of Cubic FeSi2 in Si upon Thermal Annealing

1993 ◽  
Vol 311 ◽  
Author(s):  
X.X. Lin ◽  
J. Desimoni ◽  
H. Bemas ◽  
Z. Liliental-Weber ◽  
J. Washburn
Keyword(s):  
Electron Microscopy ◽  
Thermal Annealing ◽  
Room Temperature ◽  
Ion Beam ◽  
Cubic Phase ◽  
Precipitate Coarsening ◽  
Transmission Electron ◽  
Higher Temperature ◽  
Induced Crystallization ◽  
Fe Implantation

ABSTRACTCubic FeSi2 precipitates were produced in Si (001) wafers by Fe implantation at room temperature, followed by ion beam-induced crystallization at 320°C, and their stability upon thermal annealing was examined by transmission electron microscopy. We found that the cubic phase remains relatively stable for a 650°C anneal, but the precipitates tend to change from an aligned to a twinned orientation with respect to the Si matrix. For higher temperature (800 and 900°C) anneals, most of the precipitates are transformed into β-FeSi2, accompanied by substantial precipitate coarsening. For platelet-shaped precipitates, the coarsening activation energy was determined to be 3.48 eV.

CoSi2 Precipitate Coarsening During Formation of Buried Epitaxial Cosi2 Layers By Ion Beam Synthesis

1990 ◽  
Vol 201 ◽  
Author(s):  
R. Jebasinski ◽  
S. Mantl ◽  
K. Radermacher ◽  
P. Fichtner ◽  
W. Jăger ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Activation Energy ◽  
Transmission Electron Microscopy ◽  
Cross Section ◽  
Microstructural Evolution ◽  
Annealing Temperature ◽  
Ion Beam ◽  
Precipitate Coarsening ◽  
Annealing Temperatures ◽  
Transmission Electron

AbstractThe coarsening of CoSi2 precipitates and the microstructural evolution of (111) Si implanted with 200 keV Co+ ions at 350°C and fluences of 1×1016cm−2 and 6×1016cm−2 were investigated as a function of depth, annealing temperature and annealing time using Rutherford Backscattering Spectroscopy (RBS) and Transmission Electron Microscopy (TEM). After annealing cross-section TEM micrographs show a layered array of platelet-shaped precipitates with preferred facets on {111} planes. The fraction of Co-atoms, that were redistributed during the different annealing temperatures and times, has been used to determine an activation energy for the precipitate coarsening. By applying the Meechan-Brinkman and the change-of-slope methods, we obtained activation energies in the range of 3.2 – 3.6 eV.

Room Temperature Synthesis of Cu2O Nanospheres: Optical Properties and Thermal Behavior

2014 ◽  
Vol 21 (1) ◽  
pp. 108-119 ◽  
Author(s):  
Daniela Nunes ◽  
Lídia Santos ◽  
Paulo Duarte ◽  
Ana Pimentel ◽  
Joana V. Pinto ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Thermal Behavior ◽  
Room Temperature ◽  
Diffuse Reflectance Spectroscopy ◽  
Ion Beam ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Transmission Electron

AbstractThe present work reports a simple and easy wet chemistry synthesis of cuprous oxide (Cu2O) nanospheres at room temperature without surfactants and using different precursors. Structural characterization was carried out by X-ray diffraction, transmission electron microscopy, and scanning electron microscopy coupled with focused ion beam and energy-dispersive X-ray spectroscopy. The optical band gaps were determined from diffuse reflectance spectroscopy. The photoluminescence behavior of the as-synthesized nanospheres showed significant differences depending on the precursors used. The Cu2O nanospheres were constituted by aggregates of nanocrystals, in which an on/off emission behavior of each individual nanocrystal was identified during transmission electron microscopy observations. The thermal behavior of the Cu2O nanospheres was investigated with in situ X-ray diffraction and differential scanning calorimetry experiments. Remarkable structural differences were observed for the nanospheres annealed in air, which turned into hollow spherical structures surrounded by outsized nanocrystals.

Phase Stability of the Al-Cu-Co Decagonal Phase Under Conventional Solidification

2009 ◽  
Vol 1242 ◽  
Author(s):  
J.O. Téllez-Vázquez ◽  
C. Patiño-Carachure ◽  
A. Bedolla-Jacuinde ◽  
E. García-De León ◽  
R. Pérez ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Room Temperature ◽  
Structural Model ◽  
Alloy System ◽  
Phase Region ◽  
Cubic Phase ◽  
X Ray Diffraction ◽  
Decagonal Phase ◽  
Transmission Electron ◽  
Thermal Stability Of

ABSTRACTAl65Cu15Co20 and Al67Cu13Co20 (% at.) alloys with composition near to the quasicrystalline decagonal phase was produced by melting in an induction furnace and solidified at room temperature. The structural characterization was carried out by X-ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM) and scanning electron microscopy (SEM). For the structural model of decagonal quasicrsytals, it is important to know which crystalline phases have a structural relationship on the formation and decomposition of this type of phases. In the present investigation, the decagonal phase usually coexist with small amounts of the Al(Cu,Co) cubic phase of B2 type. Then, the quasicrystalline (QC) phase is outside of a single-phase region under equilibrium conditions at room temperature. DSC and TGA techniques showed the thermal stability of the alloy system up to 1000 °C.

The formation of intermetallics in Cu/In thin films

1992 ◽  
Vol 7 (6) ◽  
pp. 1377-1386 ◽  
Author(s):  
Rita Roy ◽  
S.K. Sen ◽  
Suchitra Sen
Keyword(s):  
Electron Microscopy ◽  
Activation Energy ◽  
Grain Boundary ◽  
Room Temperature ◽  
Boundary Diffusion ◽  
Grain Boundary Diffusion ◽  
Solid State Reactions ◽  
Transmission Electron ◽  
Contact Electrical Resistance ◽  
Higher Temperature

The kinetics of the formation of intermetallics in the Cu–In bimetallic thin film couple have been studied from room temperature to 432 K by measuring the evolution of composite and contact electrical resistance with time and temperature. The resistivity measurements have been supplemented by x-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Copper reacts with indium even at room temperature to form CuIn intermetallic and assuming a model of defect assisted diffusion into the grains, the activation energy averaged over five different samples is found to be 0.40 eV. The grain boundary diffusion is found to occur with an average activation energy of 0.55 eV. XRD confirms the growth of CuIn intermetallic and on annealing at higher temperature, for copper-rich films copper further reacts with CuIn to form Cu9In4. Further evidences of solid state reactions and grain boundary diffusion through Cu grain boundaries have been obtained from SEM study. TEM indicates the growth of the grain size on annealing and confirms the presence of the CuIn phase.

Comparison Between Ion-Beam and Thermal-Annealing Induced Solid Phase Epitaxy in Fe-Implanted Si

1993 ◽  
Vol 320 ◽  
Author(s):  
X.W. Lin ◽  
J. Desimoni ◽  
H. Bernas ◽  
Z. Liliental-Weber ◽  
J. Washburn
Keyword(s):  
Electron Microscopy ◽  
Thermal Annealing ◽  
Rutherford Backscattering Spectrometry ◽  
Solid Phase ◽  
Ion Irradiation ◽  
Ion Beam ◽  
Solid Phase Epitaxy ◽  
Thermally Induced ◽  
Transmission Electron ◽  
Visible Effect

Rutherford backscattering spectrometry and transmission electron microscopy were used to compare thermally induced solid phase epitaxy (SPE) with ion-beam induced epitaxial crystallization (IBIEC) of Fe-implanted Si (001). It was found that thermal annealing leads to both Si SPE and β-FeSi2 precipitation at 520°C, but has no visible effect at 320°C. In contrast, Si SPE and FeSi2 precipitation occur at both 320 and 520°C, when ion irradiation is introduced. The precipitates grow epitaxially as γ-FeSi2 at 320°C, but consist of both β-FeSi2 and γ-FeSi2 at 520°C. It was also found that thermal annealing at 520°C results in Fe segregation toward the surface, while IBIEC basically retains the as-implanted Fe profile.

Ion Beam Induced Crystallization of Amorphous Si from NiSi2 Precipitates: An In Situ Study

1992 ◽  
Vol 279 ◽  
Author(s):  
F. Fortuna ◽  
M. -O. Ruault ◽  
H. Bernas ◽  
H. Gu ◽  
C. Colliex
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Ion Beam ◽  
In Situ Study ◽  
Transmission Electron ◽  
Interface Roughening ◽  
Amorphous Si ◽  
Induced Crystallization ◽  
Growth Shape

ABSTRACTBy first growing NiSi2 precipitates in a-Si and then irradiating with a 150 keV Si beam, we have studied ion beam induced epitaxial crystallization (IBIEC) of Si initiated at a-Si/NiSi2 precipitate interfaces. The growth shape and its temperature dependence are studied in-beam via in situ transmission electron microscopy. Interface roughening is evidenced. Preliminary results for the Co-Si system are also reported.

Size Effect in Nix(MgO)100-X Nanocomposites

2010 ◽  
Vol 168-169 ◽  
pp. 361-364 ◽  
Author(s):  
A.A. Grebennikov ◽  
O.V. Stognei
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Curie Temperature ◽  
Size Effect ◽  
Room Temperature ◽  
Ion Beam ◽  
Ion Beam Sputtering ◽  
Nanostructured Composite ◽  
Transmission Electron ◽  
Beam Sputtering

The possibility of obtaining a nanostructured composite in the Ni-Mg-O system by ion-beam sputtering has been investigated. The structural, magnetic and magnetoresistive properties of obtained samples have been investigated in a wide concentration range. The presence of the nanostructure in the obtained samples with Ni nanogranules (2-3 nm) has been confirmed by transmission electron microscopy. There is no observation of any magnetic or magnetoresistive properties at room temperature in the Nix(MgO)100-x composites. These properties were observed at 77 K. The obtained data mean that Curie temperature of the Ni nanogranules is lower then 298 K. This is due to small size of nickel granules and low value of exchange interaction energy in nickel.

Analysis of Dislocations Nucleated after Nano Indentation Tests at Room Temperature in 4H-SiC

2012 ◽  
Vol 717-720 ◽  
pp. 339-342 ◽  
Author(s):  
Jean Luc Demenet ◽  
Madyan Amer ◽  
Christophe Tromas ◽  
Jacques Rabier
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Deformation Mechanism ◽  
Indium Antimonide ◽  
Room Temperature ◽  
Nano Indentation ◽  
Transmission Electron ◽  
Indentation Tests ◽  
Spherical Indentor ◽  
Higher Temperature

4H-SiC intrinsic homoepitaxied single crystals have been nano indented at room temperature using a spherical indentor and the related deformation microstructures have been analyzed by Transmission Electron Microscopy. Dislocations are lying in the basal plane but have been found to be perfect, in contrast with observations made at higher temperature. Although such a change in deformation mechanism has been observed in other semiconductors such as Silicon and Indium Antimonide, it was unexpected in a very low stacking fault material such as SiC.

Wurtzite-to Amorphous-to Cubic Phase Transition of GaN1-XAsx Alloys with Increasing as Content

2012 ◽  
Vol 186 ◽  
pp. 74-77 ◽  
Author(s):  
Zuzanna Liliental-Weber ◽  
R. dos Reis ◽  
A. Levander ◽  
Kin M. Yu ◽  
Wladek Walukiewicz ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Growth Temperature ◽  
Structural Changes ◽  
Single Phase ◽  
Cubic Phase ◽  
Al2o3 Substrate ◽  
Columnar Growth ◽  
Transmission Electron ◽  
Higher Temperature ◽  
Z Contrast

This paper describes Transmission Electron Microscopy studies of the structural changes of GaN1-xAsx alloys grown by Molecular Beam Epitaxy at low temperatures on Al2O3 substrate. We found that by lowering the growth temperature increasing amount of As can be incorporated in GaN1-xAsx forming a single phase alloy. For the low As content a columnar growth of wurtzite structure is observed but for increasing As in the range of 0.170.75 the layer becomes amorphous. Increase in Ga flux at low growth temperature (about 200°C) leads to columnar alloys with As content >75% with a cubic structure. In addition to the structural changes monotonic change of the band gap is also observed with the As content in the alloy. The amorphous alloy is stable up to annealing at temperatures not higher than 600°C. Annealing at higher temperature leads to phase separation of GaAs:N and GaN:As confirmed by Z-contrast electron microscopy.

scholarly journals Room-Temperature Growth of SiC Thin Films by Dual-Ion-Beam Sputtering Deposition

2008 ◽  
Vol 2008 ◽  
pp. 1-5 ◽  
Author(s):  
C. G. Jin ◽  
X. M. Wu ◽  
L. J. Zhuge
Keyword(s):  
Electron Microscopy ◽  
Room Temperature ◽  
Ion Beam ◽  
Substrate Surface ◽  
Ion Beam Sputtering ◽  
Sputtering Deposition ◽  
Transmission Electron ◽  
Beam Sputtering ◽  
Dual Ion Beam Sputtering ◽  
Sic Films

Silicon carbide (SiC) films were prepared by single and dual-ion-beamsputtering deposition at room temperature. An assisted Ar+ ion beam (ion energy Ei = 150 eV) was directed to bombard the substrate surface to be helpful for forming SiC films. The microstructure and optical properties of nonirradicated and assisted ion-beam irradicated films have been characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and Raman spectra. TEM result shows that the films are amorphous. The films exposed to a low-energy assisted ion-beam irradicated during sputtering from a-SiC target have exhibited smoother and compacter surface topography than which deposited with nonirradicated. The ion-beam irradicated improves the adhesion between film and substrate and releases the stress between film and substrate. With assisted ion-beam irradicated, the density of the Si–C bond in the film has increased. At the same time, the excess C atoms or the size of the sp2 bonded clusters reduces, and the a-Si phase decreases. These results indicate that the composition of the film is mainly Si–C bond.

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