Optical and TEM characterization of phase transformation in Zn ion implanted and thermal oxidized quartz

Annales Universitatis Mariae Curie-Sklodowska sectio AAA – Physica ◽

10.17951/aaa.2016.71.71 ◽

2017 ◽

Vol 71 ◽

pp. 71

Author(s):

Vladimir Privezentsev

Keyword(s):

Phase Transformation ◽

Spectral Range ◽

Room Temperature ◽

Metal Oxide Nanoparticles ◽

Optical Parameters ◽

Average Radius ◽

Font Size ◽

Tem Characterization ◽

Temperature Ranges

<table class="data" width="100%"><tbody><tr valign="top"><td class="value">Metal and metal oxide nanoparticles (NPs) embedded in various matrices have been the object of increasing interest due to their peculiar physical properties significantly different from the corresponding ones of bulk material. Metallic Zn NPs can be used in UV photo-detectors. Zinc oxide NPs play an important role too, since ZnO has direct band gap of 3.37eV, large exiton binding energy of 60meV, sorption effect, room temperature ferromagnetism and others. So they can be used in varies perspective electron devices. In this paper the optical parameters and transmission electron microscopy (TEM) characterization of Zn implanted quartz during NP formation at annealing are reported.Optical-grade high-pure (OH-: 50ppb) amorphous quartz slides were implanted by 64Zn+ ions with fluence of 5×1016/cm2 and energy of 50keV. To avoid the magnificent substrate heating during implantation the ion current density was less than 0.5μA/cm2. Than the samples were subjected to isochronally during 1h oxidation in temperature ranges from 400 up to 800oC. The Zn contained phase creation and its thermal evolution were investigated by recording the optical transmittance spectra at room temperature in a spectral range of 200-800nm and by photoluminescence at temperatures of 10-300K in a spectral range of 350-800nm using an illumination of He-Cd laser with wavelength of 325nm. Visualization and identification of NPs was made by study of the cross section samples TEM fitted with electron diffraction, an EDAX detector attachment for X-ray energy dispersive spectroscopy (EDS), and with a high angle annular dark field detector (HAADF) for scanning operation. The EDS maps of the element distribution and the NP sizes were determined in the scanning TEM regime.As a result of these studies it was found that after the quartz implantation by 64Zn+ ions with fluence of 5×1016/cm2 and energy of 50keV the amorphous metallic Zn NPs with an average radius of 3 nm were created. During process of sequentially isochronally furnace annealing in oxygen atmosphere in 1h in temperature ranges from 400 up to 800oC in samples there was phase transformation from metallic Zn phase to its oxide form. After annealing at 800oC the Zn NPs transform to the ZnO or/and Zn2SiO4 phase with average radius of 4,5nm.</td></tr></tbody></table><div id="indexing"><h4> </h4></div>

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Fluorine-based color centers in diamond

Scientific Reports ◽

10.1038/s41598-020-78436-6 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

S. Ditalia Tchernij ◽

T. Lühmann ◽

E. Corte ◽

F. Sardi ◽

F. Picollo ◽

...

Keyword(s):

Spectral Range ◽

Room Temperature ◽

Operating Temperature ◽

Excitation Wavelength ◽

Strong Indication ◽

Experimental Parameters ◽

Range Characterization ◽

Subsequent Thermal Annealing ◽

Implantation Fluence

AbstractWe report on the creation and characterization of the luminescence properties of high-purity diamond substrates upon F ion implantation and subsequent thermal annealing. Their room-temperature photoluminescence emission consists of a weak emission line at 558 nm and of intense bands in the 600–750 nm spectral range. Characterization at liquid He temperature reveals the presence of a structured set of lines in the 600–670 nm spectral range. We discuss the dependence of the emission properties of F-related optical centers on different experimental parameters such as the operating temperature and the excitation wavelength. The correlation of the emission intensity with F implantation fluence, and the exclusive observation of the afore-mentioned spectral features in F-implanted and annealed samples provides a strong indication that the observed emission features are related to a stable F-containing defective complex in the diamond lattice.

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Dislocation dissociation in Ll2 ordered alloy Ni3Ge

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100171171 ◽

1994 ◽

Vol 52 ◽

pp. 688-689

Author(s):

J. Fang ◽

E. M. Schulson ◽

I. Baker

Keyword(s):

Yield Stress ◽

Room Temperature ◽

Complete Analysis ◽

Deformation Structure ◽

Burgers Vector ◽

Tem Characterization ◽

Perfect Dislocation ◽

Increasing Temperature ◽

Dislocation Dissociation

It is well established that the yield stress of Ni3Ge anomalously increases with increasing temperature from 77 K to 673 K. Above room temperature, the anomaly is generally attributed to the Kear-Wilsdorf (K-W) mechanism. Since no parallel systematic TEM investigation has been performed to characterize the dislocation structures in Ni3Ge, it is not clear whether the yield stress anomaly below room temperature is governed mainly by the K-W mechanism or by other mechanism(s). Thus, detailed TEM characterization of dislocation dissociation has been carried out in polycrystalline Ni3Ge deformed at room temperature. In this report, we briefly describe the main results obtained. The complete analysis can be found elsewhere.The deformation structure mainly consists of apparently undissociated dislocations with Burgers’ vector parallel to a<110> and of SISF (super intrinsic stacking fault)-coupled partials. Fig. 1 shows an example of SISF dissociation. First, consider dissociation of a perfect dislocation into partials 1 and 2.

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TEM characterization of synthetic hillebrandite: Structure, microstructure, and dehydration

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100150496 ◽

1993 ◽

Vol 51 ◽

pp. 932-933

Author(s):

Y. J. Kim ◽

W. M. Kriven

Keyword(s):

Crystal Structure ◽

Room Temperature ◽

Dark Field ◽

Fiber Axis ◽

Data Space ◽

Tem Characterization ◽

Dehydration Mechanism ◽

Fibrous Mineral

Hillebrandite (Ca2SiO4•H2O) occurs in nature as a white, fibrous mineral. Synthetic hillebrandite was prepared hydrothemally from calcia and silica. On heating, hillebrandite dehydrated to β-Ca2SiO4 which is stable at room temperature. The crystal structure, microstructures and the dehydration mechanism of the synthetic hillebrandite prepared by Ishida et. al were investigated by conventional TEM, HREM, and in situ hot-stage TEM.Most hillebrandite fibers showed their fiber axis to be parallel to the b axis and tended to lie on {001} cleavage planes. SADP’s frequently displayed continuous streaking, and corresponding dark field images revealed stacking disorders perpendicular to the fiber axis (Fig. 1). The observed [001] SADP (Fig. 2) was very different from the expected [001] SADP based on published XRD data (space group, P21/a). For all hk0 reflections, (i) if k = odd, no individual spots are shown but weak continuous streaking exists, (ii) if k = 2, reflections of h = even are extinct, and (iii) if k = 4, reflections of h = odd are extinct.

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Lead Telluride Doped with Au as a Very Promising Material for Thermoelectric Applications

Advances in Materials Science and Engineering ◽

10.1155/2015/283782 ◽

2015 ◽

Vol 2015 ◽

pp. 1-11

Author(s):

Pantelija M. Nikolic ◽

Konstantinos M. Paraskevopoulos ◽

Triantafyllia T. Zorba ◽

Zorka Z. Vasiljevic ◽

Eleni Pavlidou ◽

...

Keyword(s):

Electronic Transport ◽

Room Temperature ◽

Plasma Frequency ◽

Lead Telluride ◽

Far Infrared ◽

Optical Parameters ◽

High Quality ◽

Free Carriers ◽

Reflectivity Spectra

PbTe single crystals doped with monovalent Au or Cu were grown using the Bridgman method. Far infrared reflectivity spectra were measured at room temperature for all samples and plasma minima were registered. These experimental spectra were numerically analyzed and optical parameters were calculated. All the samples of PbTe doped with Au or Cu were of the “n” type. The properties of these compositions were analyzed and compared with PbTe containing other dopants. The samples of PbTe doped with only 3.3 at% Au were the best among the PbTe + Au samples having the lowest plasma frequency and the highest mobility of free carriers-electrons, while PbTe doped with Cu was the opposite. Samples with the lowest Cu concentration of 0.23 at% Cu had the best properties. Thermal diffusivity and electronic transport properties of the same PbTe doped samples were also investigated using a photoacoustic (PA) method with the transmission detection configuration. The results obtained with the far infrared and photoacoustic characterization of PbTe doped samples were compared and discussed. Both methods confirmed that when PbTe was doped with 3.3 at% Au, thermoelectric and electrical properties of this doped semiconductor were both significantly improved, so Au as a dopant in PbTe could be used as a new high quality thermoelectric material.

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Microstructural and Microchemical Characterization of Nickel Sulfide Inclusions in Plate Glass

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100089123 ◽

1991 ◽

Vol 49 ◽

pp. 962-963

Author(s):

J. Cooper ◽

O. Popoola ◽

W. M. Kriven

Keyword(s):

Thermal Expansion ◽

Phase Transformation ◽

Glass Matrix ◽

Nickel Sulfide ◽

Plate Glass ◽

Thermal Expansion Mismatch ◽

Volume Increase ◽

Β Phase ◽

Microchemical Characterization

Nickel sulfide inclusions have been implicated in the spontaneous fracture of large windows of tempered plate glass. Two alternative explanations for the fracture-initiating behaviour of these inclusions have been proposed: (1) the volume increase which accompanies the α to β phase transformation in stoichiometric NiS, and (2) the thermal expansion mismatch between the nickel sulfide phases and the glass matrix. The microstructure and microchemistry of the small inclusions (80 to 250 μm spheres), needed to determine the cause of fracture, have not been well characterized hitherto. The aim of this communication is to report a detailed TEM and EDS study of the inclusions.

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Characterization of intergranular cuprous oxide in polycrystalline YBa2Cu3O7-x

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100106466 ◽

1988 ◽

Vol 46 ◽

pp. 880-881

Author(s):

Bradley L. Thiel ◽

Chan Han R. P. ◽

Kurosky L. C. Hutter ◽

I. A. Aksay ◽

Mehmet Sarikaya

Keyword(s):

Grain Boundary ◽

Cuprous Oxide ◽

Room Temperature ◽

Boundary Phase ◽

Spectroscopic Techniques ◽

Transition Width ◽

Practical Applications ◽

Thin Foils ◽

Superconducting Oxides

The identification of extraneous phases is important in understanding of high Tc superconducting oxides. The spectroscopic techniques commonly used in determining the origin of superconductivity (such as RAMAN, XPS, AES, and EXAFS) are surface-sensitive. Hence a grain boundary phase several nanometers thick could produce irrelevant spectroscopic results and cause erroneous conclusions. The intergranular phases present a major technological consideration for practical applications. In this communication we report the identification of a Cu2O grain boundary phase which forms during the sintering of YBa2Cu3O7-x (1:2:3 compound).Samples are prepared using a mixture of Y2O3. CuO, and BaO2 powders dispersed in ethanol for complete mixing. The pellets pressed at 20,000 psi are heated to 950°C at a rate of 5°C per min, held for 1 hr, and cooled at 1°C per min to room temperature. The samples show a Tc of 91K with a transition width of 2K. In order to prevent damage, a low temperature stage is used in milling to prepare thin foils which are then observed, using a liquid nitrogen holder, in a Philips 430T at 300 kV.

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TEM characterization of proton-exchanged LiNbO3 optical waveguides

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010014395x ◽

1986 ◽

Vol 44 ◽

pp. 480-481

Author(s):

W. E. Lee

Keyword(s):

Refractive Index ◽

Benzoic Acid ◽

Optical Waveguides ◽

Total Internal Reflection ◽

Index Of Refraction ◽

Optical Measurements ◽

Lithium Ions ◽

Wide Channel ◽

Tem Characterization

An optical waveguide consists of a several-micron wide channel with a slightly different index of refraction than the host substrate; light can be trapped in the channel by total internal reflection.Optical waveguides can be formed from single-crystal LiNbO3 using the proton exhange technique. In this technique, polished specimens are masked with polycrystal1ine chromium in such a way as to leave 3-13 μm wide channels. These are held in benzoic acid at 249°C for 5 minutes allowing protons to exchange for lithium ions within the channels causing an increase in the refractive index of the channel and creating the waveguide. Unfortunately, optical measurements often reveal a loss in waveguiding ability up to several weeks after exchange.

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TEM characterization of WSix films

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100171973 ◽

1994 ◽

Vol 52 ◽

pp. 848-849

Author(s):

V. C. Kannan ◽

S. M. Merchant ◽

R. B. Irwin ◽

A. K. Nanda ◽

M. Sundahl ◽

...

Keyword(s):

Integrated Circuits ◽

Vapor Deposition ◽

High Purity ◽

Physical Vapor Deposition ◽

Thermal Treatments ◽

Rapid Thermal Anneal ◽

Tungsten Silicide ◽

Tem Characterization ◽

Metal Silicides

Metal silicides such as WSi2, MoSi2, TiSi2, TaSi2 and CoSi2 have received wide attention in recent years for semiconductor applications in integrated circuits. In this study, we describe the microstructures of WSix films deposited on SiO2 (oxide) and polysilicon (poly) surfaces on Si wafers afterdeposition and rapid thermal anneal (RTA) at several temperatures. The stoichiometry of WSix films was confirmed by Rutherford Backscattering Spectroscopy (RBS). A correlation between the observed microstructure and measured sheet resistance of the films was also obtained.WSix films were deposited by physical vapor deposition (PVD) using magnetron sputteringin a Varian 3180. A high purity tungsten silicide target with a Si:W ratio of 2.85 was used. Films deposited on oxide or poly substrates gave rise to a Si:W ratio of 2.65 as observed by RBS. To simulatethe thermal treatments of subsequent processing procedures, wafers with tungsten silicide films were subjected to RTA (AG Associates Heatpulse 4108) in a N2 ambient for 60 seconds at temperatures ranging from 700° to 1000°C.

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