On Nature of Resonant Transversal Kerr Effect in InMnAs and GaMnAs Layers

2010 ◽  
Vol 168-169 ◽  
pp. 35-38 ◽  
Author(s):  
E.A. Gan'shina ◽  
L.L. Golik ◽  
V.I. Kovalev ◽  
Z.E. Kun’kova ◽  
M.P. Temiryazeva ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Optical Properties ◽  
Laser Ablation ◽  
Kerr Effect ◽  
Room Temperature ◽  
Optical Constants ◽  
Cross Sectional ◽  
Transmission Electron ◽  
Resonant Character

Optical and magneto-optical properties of In(Ga)MnAs layers fabricated by laser ablation on GaAs(100) substrates were studied. Spectra of the optical constants and the transversal Kerr effect (TKE) depended substantially on the conditions of layer fabrication and testified to the presence of MnAs inclusions in all the samples. The cross-sectional transmission electron microscopy revealed the presence in the layers of inclusions 10-40 nm in size. At room temperature, a strong resonant band was observed in the TKE spectra of some In(Ga)MnAs layers in the energy range 0.5-2.7 eV. The resonant character of the TKE spectra was explained by excitation of surface plasmons in the MnAs nanoclusters embedded in the semiconductor host.

High Resolution Transmission Electron Microscopy of Proton Implanted Gallium Arsenide

1985 ◽  
Vol 46 ◽  
Author(s):  
D. K. Sadana ◽  
J. M. Zavada ◽  
H. A. Jenkinson ◽  
T. Sands
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Phenomenological Model ◽  
Room Temperature ◽  
Stacking Faults ◽  
High Dose ◽  
Cross Sectional ◽  
Projected Range ◽  
Transmission Electron

AbstractHigh resolution transmission electron microscopy (HRTEM) has been performed on cross-sectional specimens from high dose (1016 cm−2) H+ implanted (100) GaAs (300 keV at room temperature). It was found that annealing at 500°C created small (20-50Å) loops on {111} near the projected range (Rp)(3.2 μm). At 550-600°C, voids surrounded by stacking faults, microtwins and perfect dislocations were observed near the Rp. A phenomenological model explaining the observed results is proposed.

scholarly journals One pot synthesis of silver nanoparticles using a cyclodextrin containing polymer as reductant and stabilizer

2014 ◽  
Vol 5 ◽  
pp. 380-385 ◽  
Author(s):  
Arkadius Maciollek ◽  
Helmut Ritter
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Silver Nanoparticles ◽  
Optical Properties ◽  
Silver Nitrate ◽  
Room Temperature ◽  
One Pot ◽  
One Pot Synthesis ◽  
Transmission Electron ◽  
Vis Spectroscopy

A facile and one pot synthesis of silver nanoparticles with narrow size distributions using silver nitrate and a copolymer 1 from N-isopropylacrylamide (NIPAM) and mono-(1H-triazolylmethyl)-2-methylacryl-β-cyclodextrin acting as reductant and stabilizer without using any additional reducing agent is reported. The reduction was carried out in aqueous solution under pH neutral conditions at room temperature. The results of dynamic light scattering analysis and transmission electron microscopy show adjustable particle sizes from 30–100 nm, due to variation of silver nitrate concentration, the polymeric reducing and stabilisation agent concentration or reaction time. The spherical structure of the silver nanoparticles has been confirmed by UV–vis spectroscopy and transmission electron microscopy. The optical properties of the nanoparticles have also been characterized by fluorescence spectroscopy. The formed spherical particles are stable in aqueous medium at room temperature over a period of several weeks. Furthermore the changes in the optical properties of the nanoparticles due to thermo induced volume phase transition behavior of the thermoresponsive cyclodextrin containing polymer 1 have been characterized by UV–vis spectroscopy.

SYNTHESIS OF CdTe NANOPARTICLE BY γ-IRRADIATION

2002 ◽  
Vol 01 (05n06) ◽  
pp. 581-585
Author(s):  
SONG JA JO ◽  
YOUNG SOO KANG
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Optical Properties ◽  
Powder Diffraction ◽  
Room Temperature ◽  
Γ Irradiation ◽  
X Ray ◽  
Pl Spectra ◽  
Cdte Nanoparticles ◽  
Transmission Electron

Semiconductor CdTe nanoparticles were synthesized by the γ-irradiation of Cd ion complex at room temperature. Cd-olate complex was reacted with aqueous NaHTe solution. The products were investigated by X-ray Powder Diffraction (XRD) and Transmission Electron Microscopy (TEM). The optical properties of CdTe were investigated with UV-vis and photoluminescence (PL) spectra.

Growth of Epitaxial CoSi2/Si Multilayers

1986 ◽  
Vol 77 ◽  
Author(s):  
B. D. Runt ◽  
N. Lewis ◽  
L. J. Schotalter ◽  
E. L. Hall ◽  
L. G. Turner
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Room Temperature ◽  
Solid Phase ◽  
Multilayer Structures ◽  
Solid Phase Epitaxy ◽  
Cross Sectional ◽  
Temperature Growth ◽  
Transmission Electron

ABSTRACTEpitaxial CoSi2/Si multilayers have been grown on Si(111) substrates with up to four bilayers of suicide and Si. To our knowledge, these are the first reported epitaxial metal-semiconductor multilayer structures. The growth of these heterostructures is complicated by pinhole formation in the suicide layers and by nonuniform growth of Si over the suicide films, but these problems can be controlled through nse of proper growth techniques. CoSi2 pinhole formation has been significantly reduced by utilizing a novel solid phase epitaxy technique in which room-temperature-deposited Co/Si bilayers are annealed to 600–650δC to form the suicide layers. Islanding in the Si layers is minimized by depositing a thin (<100Å) Si layer at room temperature with subsequent high temperature growth of the remainder of the Si. Cross-sectional transmission electron microscopy studies demonstrate that these growth procedures dramatically improve the continuity and quality of the CoSi. and Si multilayers.

Implant Damage in AlGaAs Based Superlattices and Alloys at 77K

1989 ◽  
Vol 147 ◽  
Author(s):  
E. A. Dobisz ◽  
H. Dietrich ◽  
A. W. McCormick ◽  
J. P. Harbison
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Layer Thickness ◽  
Room Temperature ◽  
Amorphous Layer ◽  
Current Work ◽  
Cross Sectional ◽  
Bulk Gaas ◽  
Transmission Electron ◽  
Extensive Damage

AbstractPreviously, it was shown that superlattices implanted with Si at 77K, exhibited more extensive damage and uniform compositional mixing upon subsequent annealing than samples implanted at room temperature.[l,2] The current work focuses on the damage in samples implanted with Si at 77K. The study shows that for a given dose, the amount of damage depends upon the layer thickness and the composition. Specimens of bulk GaAs, Al 3Ga. 7As, 7.5 nm GaAs -10 nm Al. 3Ga. 7As superlattice (SL1), 5.5 nm GaAs −3.5 nm AlAs superlattice (SL2), and 8.0 nm GaAs −8.0 nm AlAs superlat-tice (SL3) were implanted at 77K with 100 KeV Si, with doses ranging from 3 × 1013 cm−2 to 1 × 1015 cm−2. The samples were examined by ion channelling and cross sectional transmission electron microscopy (TEM). At 77K and a dose of 1 × 1014 cm−2, the GaAs and SLi showed an amorphous layer, while no damage peak was observed in SL2. The 77K amorphization thresholds of the Al 3Ga. 7As alloy, SL2, and SL3 were 2.5 × 1014 cm−2, 4 × 1014 cm−2, and 1 × 1015 cm−2 respectively. The sharpness of the amorphization threshold varied with the material.

Microstructure of Sputter Deposited TiO2/SiO2 Multilayer Optical Coatings

2000 ◽  
Vol 654 ◽  
Author(s):  
E. Sutter ◽  
P. Sutter ◽  
J.J. Moore
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Optical Properties ◽  
Low Temperature ◽  
Optical Filters ◽  
Optical Coatings ◽  
Cross Sectional ◽  
Transmission Electron ◽  
Improved Stability ◽  
Sputter Deposited

AbstractThe microstructure of TiO2/SiO2 multilayer optical filters has been investigated in detail by cross-sectional transmission electron microscopy and related to their optical properties and stability. The amorphous TiO2 layers in the as-deposited multilayers are found to consist of nanocolumns and intercolumnar regions with non-stoichiometric or lower density material. In humid ambients this microstructure absorbs moisture which causes a shift in the absorption edge of the filters. Upon annealing the TiO2layers are found to recrystallize into the low-temperature anatase modification which leads to significantly improved stability of the optical properties of the filters.

THE EXCHANGE-BIASING IN THE TOP-CONFIGURATION Ni80Fe20/Ir20Mn80 SYSTEM

2009 ◽  
Vol 23 (06n07) ◽  
pp. 1658-1662
Author(s):  
YUAN-TSUNG CHEN
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Room Temperature ◽  
Cross Sectional ◽  
X Ray ◽  
Exchange Biasing ◽  
Plane Field ◽  
Transmission Electron ◽  
Resolution Electron ◽  
Optimal Values

In this work, top-configuration exchange-biasing NiFe ( y )/ IrMn (90Å) systems have been investigated with three different conditions: (a) the substrate temperature ( T s ) was kept at room temperature (RT) only, (b) T s at RT with an in-plane field ( h ) = 500 Oe deposition during deposition, and (c) T s = RT with h during deposition and postdeposition annealing in the field at T A = 250° C for 1h, with the samples field cooled to RT. High resolution electron cross-sectional transmission electron microscopy (HR X-TEM) and x-ray results reveal that the IrMn (111) texturing plays a key role in the exchange-biasing field ( H ex ) and interfacial energy ( J k ). The H ex versus y result shows that H ex increases when y decreases. Since J k = H ex M s y , where M s is NiFe magnetization, it is easy to derive H ex = J k /( M s y ). Therefore, if H ex is inversely proportional to y , with J k / M s constant, we find H ex y = constant. In short, the y dependence of J k is similar to that of M s for each curve. The H c is inversely proportional to y because of the surface pinning effects from the Ta / NiFe and NiFe / IrMn interfaces. Finally, the optimal values for H ex and J k are 220 Oe and 0.075 erg/cm2, respectively.

Scanning and Transmission Electron Microscopy of Human Red Blood Cells

1969 ◽  
Vol 27 ◽  
pp. 44-45
Author(s):  
A.J. Tousimis ◽  
T.R. Padden
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Blood Cells ◽  
Room Temperature ◽  
Type Specimen ◽  
New Combination ◽  
Human Red Blood Cells ◽  
Transmission Electron ◽  
Microscope Slides ◽  
Scanning Electron

The size, shape and surface morphology of human erythrocytes (RBC) were examined by scanning electron microscopy (SEM), of the fixed material directly and by transmission electron microscopy (TEM) of surface replicas to compare the relative merits of these two observational procedures for this type specimen.A sample of human blood was fixed in glutaraldehyde and washed in distilled water by centrifugation. The washed RBC's were spread on freshly cleaved mica and on aluminum coated microscope slides and then air dried at room temperature. The SEM specimens were rotary coated with 150Å of 60:40- gold:palladium alloy in a vacuum evaporator using a new combination spinning and tilting device. The TEM specimens were preshadowed with platinum and then rotary coated with carbon in the same device. After stripping the RBC-Pt-C composite film, the RBC's were dissolved in 2.5N HNO3 followed by 0.2N NaOH leaving the preshadowed surface replicas showing positive topography.

Formation of Dislocation Channels in Neutron Irradiated Molybdenum

1972 ◽  
Vol 30 ◽  
pp. 672-673
Author(s):  
S. Mahajan
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Ambient Temperature ◽  
Room Temperature ◽  
Channel Formation ◽  
Early Stages ◽  
Transmission Electron ◽  
Three Stages ◽  
Two Stages ◽  
Polycrystalline Molybdenum

The evolution of dislocation channels in irradiated metals during deformation can be envisaged to occur in three stages: (i) formation of embryonic cluster free regions, (ii) growth of these regions into microscopically observable channels and (iii) termination of their growth due to the accumulation of dislocation damage. The first two stages are particularly intriguing, and we have attempted to follow the early stages of channel formation in polycrystalline molybdenum, irradiated to 5×1019 n. cm−2 (E > 1 Mev) at the reactor ambient temperature (∼ 60°C), using transmission electron microscopy. The irradiated samples were strained, at room temperature, up to the macroscopic yield point.Figure 1 illustrates the early stages of channel formation. The observations suggest that the cluster free regions, such as A, B and C, form in isolated packets, which could subsequently link-up to evolve a channel.

Microstructure of laser-irradiated, conducting Kapton polyimide

1995 ◽  
Vol 53 ◽  
pp. 502-503
Author(s):  
D. L. Callahan ◽  
Z. Ball ◽  
H. M. Phillips ◽  
R. Sauerbrey
Keyword(s):  
Electron Microscopy ◽  
Phase Transition ◽  
Transmission Electron Microscopy ◽  
Cross Section ◽  
Film Surface ◽  
Cross Sectional ◽  
General Utility ◽  
Transmission Electron ◽  
Considerable Debate ◽  
Potential Applications

Ultraviolet laser-irradiation can be used to induce an insulator-to-conductor phase transition on the surface of Kapton polyimide. Such structures have potential applications as resistors or conductors for VLSI applications as well as general utility electrodes. Although the percolative nature of the phase transformation has been well-established, there has been little definitive work on the mechanism or extent of transformation. In particular, there has been considerable debate about whether or not the transition is primarily photothermal in nature, as we propose, or photochemical. In this study, cross-sectional optical microscopy and transmission electron microscopy are utilized to characterize the nature of microstructural changes associated with the laser-induced pyrolysis of polyimide.Laser-modified polyimide samples initially 12 μm thick were prepared in cross-section by standard ultramicrotomy. Resulting contraction in parallel to the film surface has led to distortions in apparent magnification. The scale bars shown are calibrated for the direction normal to the film surface only.

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