High-Energy Elevated Temperature Si and Room Temperature B Implants in InP

1991 ◽  
Vol 240 ◽  
Author(s):  
R. K. Nadella ◽  
J. Vellanki ◽  
M. V. Rao
Keyword(s):  
Heat Treatment ◽  
Elevated Temperature ◽  
Energy Range ◽  
Carrier Concentration ◽  
Carrier Mobility ◽  
Room Temperature ◽  
High Energy ◽  
Fluence Range

ABSTRACTHigh-energy (3 MeV) Si implantations were performed in InP:Fe at an elevated temperature of 200 °C for fluences 8×1014, 2×1015, and 5×1015 cm“2. For the 8×1014 cm−2 fluence, an activation of 82 %, carrier mobility of 1200 cm2/V-s, a peak carrier concentration of 9×1018 cm−3, and lattice quality comparable to that of virgin crystal were obtained. No amorphization takes place for any of the fluences used. Boron compensation implantations were performed in InP:Sn (n sime 2×1018 cm3) at room temperature in the energy range 1 to 5 MeV and fluence range 1011 to 1015 cm−2. After heat treatment, maximum resistivity of the order of 106 Ω-cm was obtained in B implanted InP.

scholarly journals Investigation of Atmospheric Moisture during Heat Treatment of Glass Fibres

Fibers ◽  
2019 ◽  
Vol 7 (4) ◽  
pp. 27 ◽  
Author(s):  
Peter Jenkins ◽  
Liu Yang ◽  
James Thomason
Keyword(s):  
Heat Treatment ◽  
Tensile Strength ◽  
Elevated Temperature ◽  
Glass Fibre ◽  
Room Temperature ◽  
Strength Loss ◽  
Fibre Strength ◽  
Atmospheric Moisture ◽  
Glass Fibres ◽  
Alternative Theories

The tensile strength of single water-sized E-glass fibres that were thermally conditioned, either in air or under vacuum, was investigated. The vacuum removed water from the conditioning atmosphere, as well as the fibre surfaces, at room temperature but retained tensile strength of fibres treated in the absence of water were not significantly different from those thermally conditioned in a standard air furnace. The results suggest that water, either in the treatment atmosphere or on the surface of the fibres, is not a significant factor in fundamental glass fibre strength loss at an elevated temperature. It may, therefore, be necessary to consider alternative theories to explain this strength loss.

scholarly journals Влияние термообработки на электрические характеристики полуизолирующих слоев, полученных с помощью облучения n-SiC высокоэнергетическими ионами аргона

2018 ◽  
Vol 44 (6) ◽  
pp. 11 ◽  
Author(s):  
П.А. Иванов ◽  
А.С. Потапов ◽  
М.Ф. Кудояров ◽  
М.А. Козловский ◽  
Т.П. Самсонова
Keyword(s):  
Heat Treatment ◽  
Silicon Carbide ◽  
Room Temperature ◽  
High Energy ◽  
Room Temperature Resistivity ◽  
Electrical Characteristics ◽  
Near Surface ◽  
Heat Treated ◽  
Argon Ions ◽  
Temperature Resistivity

AbstractIrradiation of crystalline n -type silicon carbide ( n -SiC) with high-energy (53-MeV) argon ions was used to create near-surface semi-insulating ( i -SiC) layers. The influence of subsequent heat treatment on the electrical characteristics of i -SiC layers has been studied. The most high-ohmic ion-irradiated i -SiC layers with room-temperature resistivity of no less than 1.6 × 10^13 Ω cm were obtained upon the heat treatment at 600°C, whereas the resistivity of such layers heat-treated at 230°C was about 5 × 10^7 Ω cm.

Egg-shell structured LiCoO2 by Cu2+ substitution to Li+ sites via facile stirring in an aqueous copper(ii) nitrate solution

2017 ◽  
Vol 5 (47) ◽  
pp. 24892-24900 ◽  
Author(s):  
Jaemin Kim ◽  
Hyunchul Kang ◽  
Nakgyu Go ◽  
Seonghun Jeong ◽  
Taeeun Yim ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Aqueous Solution ◽  
Lithium Ion Batteries ◽  
Room Temperature ◽  
Nitrate Solution ◽  
Lithium Ion ◽  
High Energy ◽  
Egg Shell

For practical, high-energy lithium ion batteries, we introduce an egg-shell structured LiCoO2, enabling a credible performance with a high cut-off potential of 4.4 V, simply prepared by only stirring in 0.5 mM Cu(NO3)2 aqueous solution at room temperature without costly heat treatment.

scholarly journals Evaluation of the Effect of Silica Fume on Amorphous Fly Ash Geopolymers Exposed to Elevated Temperature

2021 ◽  
Vol 7 (1) ◽  
pp. 9
Author(s):  
Ong Huey Li ◽  
Liew Yun-Ming ◽  
Heah Cheng-Yong ◽  
Ridho Bayuaji ◽  
Mohd Mustafa Al Bakri Abdullah ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Compressive Strength ◽  
Elevated Temperature ◽  
Fly Ash ◽  
Silica Fume ◽  
Room Temperature ◽  
Lower Degree ◽  
Crystalline Phases ◽  
Alkali Activator

The properties of amorphous geopolymer with silica fume addition after heat treatment was rarely reported in the geopolymer field. Geopolymer was prepared by mixing fly ash and alkali activator. The silica fume was added in 2% and 4% by weight. The geopolymer samples were cured at room temperature for 28 days before exposed to an elevated temperature up to 1000 °C. The incorporation of 2% silica fume did not cause significant improvement in the compressive strength of unexposed geopolymer. Higher silica fume content of 4% reduced the compressive strength of the unexposed geopolymer. When subjected to elevated temperature, geopolymer with 2% silica fume retained higher compressive strength at 1000 °C. The addition of silica fume in fly ash geopolymer caused a lower degree of shrinkage and expansion, as compared to geopolymer without the addition of silica fume. Crystalline phases of albite and magnetite were formed in the geopolymer at 1000 °C.

Structural transformations of alumina by high energy ball milling

1993 ◽  
Vol 8 (11) ◽  
pp. 2985-2992 ◽  
Author(s):  
P.A. ZielińAski ◽  
R. Schulz ◽  
S. Kaliaguine ◽  
A. Van Neste
Keyword(s):  
Heat Treatment ◽  
High Temperature ◽  
Ball Milling ◽  
Room Temperature ◽  
High Energy ◽  
Structural Transformations ◽  
High Energy Ball Milling ◽  
Second Step ◽  
Transformation Rate ◽  
Energy Ball

Room temperature, high energy ball milling was applied to various transition aluminas (γ, K, χ), producing thermodynamically stable α-alumina–a phenomenon that could otherwise be achieved only by high temperature (1100–1200 °C) heat treatment. The transformation proceeds in two steps. The first one consists of rapid microstructural rearrangements with continuously increasing α-transformation rate. In the second step (1–2 h from the start), only relatively small changes in morphology are observed with a constant α-transformation rate. The rate is influenced only by the milling intensity. The presence or the absence of oxygen in the milling atmosphere has a large influence on the final surface area of α-alumina.

The C14-to-C15 Transformation in Cr2Hf

1994 ◽  
Vol 364 ◽  
Author(s):  
K. S. Kumar ◽  
P. M. Hazzledine
Keyword(s):  
Heat Treatment ◽  
Phase Diagram ◽  
Solid Solution ◽  
Elevated Temperature ◽  
Room Temperature ◽  
Single Phase ◽  
Higher Order ◽  
Two Phase ◽  
Heat Treated ◽  
Order Structures

AbstractThree alloys, single-phase Cr2Hf, a two-phase alloy consisting of Cr solid solution and Cr2Hf, and a two-phase alloy consisting of Hf solid solution and Cr2Hf were cast and heat treated. The C14-to- C15 transformation of the Laves phase, Cr2Hf was studied as a function of heat treatment. According to the existing phase diagram, the Cr2Hf phase exhibits a C14 structure at elevated temperature but transforms to the C15 structure at lower temperatures. Such transformations are known to be extremely sluggish. In the present study, the Cr2Hf phase was found to retain the C14 structure at room temperature in all three compositions in the cast or cast and forged conditions; upon subsequent heat-treatment at various temperatures and time-at-temperatures, however, the C14 structure decomposes to a variety of higher order structures including the 16H, 10H, and 4H structures. These superstructures can be viewed as containing various percentages of the cubic and hexagonal stacking. The C15 structure was not observed for any of the conditions considered.

Study of the Viability to Obtain Quasicrystal in the Composition AlCuFe Using High-Energy Milling, Followed by Pressing and Sintering

2010 ◽  
Vol 660-661 ◽  
pp. 426-431
Author(s):  
Rodrigo Estevam Coelho ◽  
Ramon Mateus Santos Cruz ◽  
Paulo Jesus Costa Esteves ◽  
Silvana Garcia Viana ◽  
Severino Jackson Guedes de Lima
Keyword(s):  
Heat Treatment ◽  
Mechanical Alloying ◽  
Optical Microscopy ◽  
Room Temperature ◽  
Fixed Time ◽  
High Energy ◽  
Future Research ◽  
Nominal Composition ◽  
X Ray ◽  
Setting Parameters

This work was observed the phase formations of the mixture Al-Cu-Fe processed vial mechanical alloying, powders pressing at room temperature and subsequent heat treatment. The mixture of powders was made on the nominal composition Al65Cu20Fe15. A mill of high energy of the horizontal atrittor type was used to process the powders mixtures, in fixed time of two hours of milling. After milling, the powders were pressing in a die closed, with a diameter of about 28mm. The samples were observed by optical microscopy and analyzed X-ray diffractometry. The results obtained in this study provide a basis for setting parameters may be used as a basis for future research and possible applications.

scholarly journals Tuning Green to Red Color in Erbium Niobate Micro- and Nanoparticles

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 660
Author(s):  
Susana Devesa ◽  
Joana Rodrigues ◽  
Sílvia Soreto Teixeira ◽  
Aidan P. Rooney ◽  
Manuel P. F. Graça ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Optical Properties ◽  
Room Temperature ◽  
Sol Gel ◽  
High Energy ◽  
Site Symmetry ◽  
Photoluminescence Spectra ◽  
Heat Treated ◽  
Red Color ◽  
Optical Activation

Tetragonal Er0.5Nb0.5O2 and monoclinic ErNbO4 micro- and nanoparticles were prepared by the citrate sol–gel method and heat-treated at temperatures between 700 and 1600 °C. ErNbO4 revealed a spherical-shaped crystallite, whose size increased with heat treatment temperatures. To assess their optical properties at room temperature (RT), a thorough spectroscopic study was conducted. RT photoluminescence (PL) spectroscopy revealed that Er3+ optical activation was achieved in all samples. The photoluminescence spectra show the green/yellow 2H11/2, 4S3/2→4I15/2 and red 4F9/2→4I15/2 intraionic transitions as the main visible recombination, with the number of the crystal field splitting Er3+ multiplets reflecting the ion site symmetry in the crystalline phases. PL excitation allows the identification of Er3+ high-energy excited multiplets as the preferential population paths of the emitting levels. Independently of the crystalline structure, the intensity ratio between the green/yellow and red intraionic transitions was found to be strongly sensitive to the excitation energy. After pumping the samples with a resonant excitation into the 4G11/2 excited multiplet, a green/yellow transition stronger than the red one was observed, whereas the reverse occurred for higher excitation photon energies. Thus, a controllable selective excited tunable green to red color was achieved, which endows new opportunities for photonic and optoelectronic applications.

The Influence of Mo on the Physical and Mechanical Properties of Single Crystalline Nial

1994 ◽  
Vol 364 ◽  
Author(s):  
J. Hu ◽  
V. Levit ◽  
M. J. Kaufmann
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Elevated Temperature ◽  
Tensile Properties ◽  
Room Temperature ◽  
Physical And Mechanical Properties ◽  
Considerable Influence ◽  
Single Crystalline

AbstractThe room and elevated temperature (300°C and 600°C) tensile properties of single crystalline NiAl with and without molybdenum additions have been investigated. It is shown that 0.2at% molybdenum has a considerable influence on the mechanical properties of NiAl and this influence is sensitive to heat treatment. At room temperature, the ductility of the Mo-doped alloy was higher than the binary NiAl after appropriate heat treatment. Furthermore, the elongations observed are highest at 300°C and are related to greater uniformity of deformation.

scholarly journals Restructured single parabolic band model for quick analysis in thermoelectricity

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Jianbo Zhu ◽  
Xuemei Zhang ◽  
Muchun Guo ◽  
Jingyu Li ◽  
Jinsuo Hu ◽  
...  
Keyword(s):  
Fermi Level ◽  
Carrier Concentration ◽  
Carrier Mobility ◽  
Optimization Design ◽  
State Of The Art ◽  
Band Model ◽  
Carrier Effective Mass ◽  
Intermediate Variables ◽  
Level Calculation ◽  
Spb Model

AbstractThe single parabolic band (SPB) model has been widely used to preliminarily elucidate inherent transport behaviors of thermoelectric (TE) materials, such as their band structure and electronic thermal conductivity, etc. However, in the SPB calculation, it is necessary to determine some intermediate variables, such as Fermi level or the complex Fermi-Dirac integrals. In this work, we establish a direct carrier-concentration-dependent restructured SPB model, which eliminates Fermi-Dirac integrals and Fermi level calculation and emerges stronger visibility and usability in experiments. We have verified the reliability of such restructured model with 490 groups of experimental data from state-of-the-art TE materials and the relative error is less than 2%. Moreover, carrier effective mass, intrinsic carrier mobility and optimal carrier concentration of these materials are systematically investigated. We believe that our work can provide more convenience and accuracy for thermoelectric data analysis as well as instructive understanding on future optimization design.

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