Room-temperature and high-temperature magnetic permeability of Co-doped nanocrystalline alloys

Rare Metals ◽  
2018 ◽  
Vol 37 (5) ◽  
pp. 427-432 ◽  
Author(s):  
Bin Fu ◽  
Jie Han ◽  
Sheng-Qi Guo ◽  
Zhi Wang ◽  
Pan Zhang ◽  
...  
Keyword(s):  
High Temperature ◽  
Magnetic Permeability ◽  
Room Temperature ◽  
Nanocrystalline Alloys ◽  
Co Doped

Thermoelectric Properties of Er-doped InGaN Alloys for High Temperature Applications

2011 ◽  
Vol 1325 ◽  
Author(s):  
K. Aryal ◽  
I. W. Feng ◽  
B. N. Pantha ◽  
J. Li ◽  
J. Y. Lin ◽  
...  
Keyword(s):  
High Temperature ◽  
Room Temperature ◽  
Chemical Vapor ◽  
Organic Chemical ◽  
Metal Organic ◽  
Er Doped ◽  
Organic Chemical Vapor Deposition ◽  
Co Doped ◽  
Ingan Alloys ◽  
Temperature Applications

ABSTRACTThermoelectric (TE) properties of erbium-silicon co-doped InxGa1-xN alloys (InxGa1-xN: Er + Si, 0≤x≤0.14), grown by metal organic chemical vapor deposition, have been investigated. It was found that doping of InGaN alloys with Er atoms of concentration, N[Er] larger than 5x1019 cm-3, has substantially reduced the thermal conductivity, κ, in low In content InGaN alloys. It was observed that κ decreases as N[Er] increases in Si co-doped In0.10Ga0.90N alloys. A room temperature ZT value of ~0.05 was obtained in In0.14Ga0.86N: Er + Si, which is much higher than that obtained in un-doped InGaN with similar In content. Since low In content InGaN is stable at high temperatures, these Er+Si co-doped InGaN alloys could be promising TE materials for high temperature applications.

ABOUT HEAT CAPACITY OF TITANIUM CARBIDE TiCx

2019 ◽  
pp. 56-66
Author(s):  
I. Khidirov ◽  
V. V. Getmanskiy ◽  
A. S. Parpiev ◽  
Sh. A. Makhmudov
Keyword(s):  
Heat Capacity ◽  
High Temperature ◽  
Titanium Carbide ◽  
Temperature Dependence ◽  
Carbon Concentration ◽  
Room Temperature ◽  
Thermodynamic Characteristics ◽  
Liquid Nitrogen Temperature ◽  
Analysis Data ◽  
Thermal Excitation

This work relates to the field of thermophysical parameters of refractory interstitial alloys. The isochoric heat capacity of cubic titanium carbide TiCx has been calculated within the Debye approximation in the carbon concentration  range x = 0.70–0.97 at room temperature (300 K) and at liquid nitrogen temperature (80 K) through the Debye temperature established on the basis of neutron diffraction analysis data. It has been found out that at room temperature with decrease of carbon concentration the heat capacity significantly increases from 29.40 J/mol·K to 34.20 J/mol·K, and at T = 80 K – from 3.08 J/mol·K to 8.20 J/mol·K. The work analyzes the literature data and gives the results of the evaluation of the high-temperature dependence of the heat capacity СV of the cubic titanium carbide TiC0.97 based on the data of neutron structural analysis. It has been proposed to amend in the Neumann–Kopp formula to describe the high-temperature dependence of the titanium carbide heat capacity. After the amendment, the Neumann–Kopp formula describes the results of well-known experiments on the high-temperature dependence of the heat capacity of the titanium carbide TiCx. The proposed formula takes into account the degree of thermal excitation (a quantized number) that increases in steps with increasing temperature.The results allow us to predict the thermodynamic characteristics of titanium carbide in the temperature range of 300–3000 K and can be useful for materials scientists.

Nanocomposite Polyurethane Foams Via POSS Blends

2002 ◽  
Vol 733 ◽  
Author(s):  
Brock McCabe ◽  
Steven Nutt ◽  
Brent Viers ◽  
Tim Haddad
Keyword(s):  
High Temperature ◽  
Sample Preparation ◽  
Room Temperature ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Polyurethane Foams ◽  
Development Projects ◽  
Polymer Systems ◽  
Polyurethane Resin ◽  
Military Development

AbstractPolyhedral Oligomeric Silsequioxane molecules have been incorporated into a commercial polyurethane formulation to produce nanocomposite polyurethane foam. This tiny POSS silica molecule has been used successfully to enhance the performance of polymer systems using co-polymerization and blend strategies. In our investigation, we chose a high-temperature MDI Polyurethane resin foam currently used in military development projects. For the nanofiller, or “blend”, Cp7T7(OH)3 POSS was chosen. Structural characterization was accomplished by TEM and SEM to determine POSS dispersion and cell morphology, respectively. Thermal behavior was investigated by TGA. Two methods of TEM sample preparation were employed, Focused Ion Beam and Ultramicrotomy (room temperature).

FANSTEEL 85 METAL

Alloy Digest ◽  
1981 ◽  
Vol 30 (6) ◽  
Keyword(s):  
High Temperature ◽  
Physical Properties ◽  
Creep Strength ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Base Alloy ◽  
Heat Treating ◽  
Good Combination ◽  
Bend Strength ◽  
Temperature Performance

Abstract FANSTEEL 85 METAL is a columbium-base alloy characterized by good fabricability at room temperature, good weldability and a good combination of creep strength and oxidation resistance at elevated temperatures. Its applications include missile and rocket components and many other high-temperature parts. This datasheet provides information on composition, physical properties, microstructure, hardness, elasticity, tensile properties, and bend strength as well as creep. It also includes information on low and high temperature performance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: Cb-7. Producer or source: Fansteel Metallurgical Corporation. Originally published December 1963, revised June 1981.

MAGNESIUM AZ31B

Alloy Digest ◽  
1962 ◽  
Vol 11 (9) ◽  
Keyword(s):  
High Temperature ◽  
Magnesium Alloy ◽  
Physical Properties ◽  
Room Temperature ◽  
Heat Treating ◽  
General Purpose ◽  
Bearing Strength ◽  
Temperature Performance ◽  
Wrought Magnesium Alloy ◽  
Metal Products

Abstract Magnesium AZ31B is a general purpose wrought magnesium alloy for room temperature service. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and compressive, shear, and bearing strength as well as creep. It also includes information on low and high temperature performance as well as forming, heat treating, machining, and joining. Filing Code: Mg-53. Producer or source: The Dow Metal Products Company.

Photoluminescence and Magnetic Properties of Undoped and (Mn, Co) co-doped ZnO Nanoparticles

2020 ◽  
Vol 16 (4) ◽  
pp. 655-666
Author(s):  
Mona Rekaby
Keyword(s):  
Magnetic Properties ◽  
Zno Nanoparticles ◽  
Room Temperature ◽  
Magnetic Measurements ◽  
Structural Defects ◽  
Ferromagnetic Behavior ◽  
Secondary Phases ◽  
Antiferromagnetic Ordering ◽  
Doped Zno ◽  
Co Doped

Objective: The influence of Manganese (Mn2+) and Cobalt (Co2+) ions doping on the optical and magnetic properties of ZnO nanoparticles was studied. Methods: Nanoparticle samples of type ZnO, Zn0.97Mn0.03O, Zn0.96Mn0.03Co0.01O, Zn0.95Mn0.03 Co0.02O, Zn0.93Mn0.03Co0.04O, and Zn0.91Mn0.03Co0.06O were synthesized using the wet chemical coprecipitation method. Results: X-ray powder diffraction (XRD) patterns revealed that the prepared samples exhibited a single phase of hexagonal wurtzite structure without any existence of secondary phases. Transmission electron microscope (TEM) images clarified that Co doping at high concentrations has the ability to alter the morphologies of the samples from spherical shaped nanoparticles (NPS) to nanorods (NRs) shaped particles. The different vibrational modes of the prepared samples were analyzed through Fourier transform infrared (FTIR) measurements. The optical characteristics and structural defects of the samples were studied through Photoluminescence (PL) spectroscopy. PL results clarified that Mn2+ and Co2+ doping quenched the recombination of electron-hole pairs and enhanced the number of point defects relative to the undoped ZnO sample. Magnetic measurements were carried out at room temperature using a vibrating sample magnetometer (VSM). (Mn, Co) co-doped ZnO samples exhibited a ferromagnetic behavior coupled with paramagnetic and weak diamagnetic contributions. Conclusion: Mn2+ and Co2+ doping enhanced the room temperature Ferromagnetic (RTFM) behavior of ZnO. In addition, the signature for antiferromagnetic ordering between the Co ions was revealed. Moreover, a strong correlation between the magnetic and optical behavior of the (Mn, Co) co-doped ZnO was analyzed.

Single–atom manganese and nitrogen co-doped graphene as low-cost catalysts for the efficient CO oxidation at room temperature

2021 ◽  
Vol 536 ◽  
pp. 147809
Author(s):  
Mingming Luo ◽  
Zhao Liang ◽  
Chao Liu ◽  
Xiaopeng Qi ◽  
Mingwei Chen ◽  
...  
Keyword(s):  
Co Oxidation ◽  
Room Temperature ◽  
Low Cost ◽  
Single Atom ◽  
Doped Graphene ◽  
Co Doped

Mechanical Alloying Behavior in the Nb-Si, Ta-Si, and Nb-Ta-Si Systems

1988 ◽  
Vol 133 ◽  
Author(s):  
K. S. Kumar ◽  
S. K. Mannan
Keyword(s):  
High Temperature ◽  
Mechanical Alloying ◽  
Mechanical Milling ◽  
Room Temperature ◽  
Crystalline Compound ◽  
X Ray Diffraction ◽  
X Ray ◽  
Β Phase ◽  
Α Phase

ABSTRACTThe mechanical alloying behavior of elemental powders in the Nb-Si, Ta-Si, and Nb-Ta-Si systems was examined via X-ray diffraction. The line compounds NbSi2 and TaSi2 form as crystalline compounds rather than amorphous products, but Nb5Si3 and Ta5Si3, although chemically analogous, respond very differently to mechanical milling. The Ta5Si3 composition goes directly from elemental powders to an amorphous product, whereas Nb5Si3 forms as a crystalline compound. The Nb5Si3 compound consists of both the tetragonal room-temperature α phase (c/a = 1.8) and the tetragonal high-temperature β phase (c/a = 0.5). Substituting increasing amounts of Ta for Nb in Nb5Si3 initially stabilizes the α-Nb5Si3 structure preferentially, and subsequently inhibits the formation of a crystalline compound.

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