Thermoelectric transport of semiconductor full-Heusler VFe2Al

2020 ◽  
Vol 8 (30) ◽  
pp. 10174-10184
Author(s):  
Shashwat Anand ◽  
Ramya Gurunathan ◽  
Thomas Soldi ◽  
Leah Borgsmiller ◽  
Rachel Orenstein ◽  
...  
Keyword(s):  
High Temperature ◽  
Seebeck Coefficient ◽  
Band Gap ◽  
Thermoelectric Transport ◽  
Resistivity Data ◽  
Wide Range ◽  
Small Band ◽  
Full Heusler ◽  
Temperature Resistivity

Seebeck coefficient of VFe2Al over a wide range of doping levels can be explained only with a small band-gap (Eg) range of 0.02–0.04 eV. This Eg value is also consistent with high-temperature resistivity data of nominally stoichiometric VFe2Al.

Thermoelectric Properties of Sm Doped CaMnO3 Using Density Functional Theory Method

2020 ◽  
Vol 1010 ◽  
pp. 334-338
Author(s):  
Abdullah Chik ◽  
Ruhiyuddin Mohd Zaki ◽  
Akeem Adekunle Adewale ◽  
Faizul Che Pa ◽  
Yeoh Cheow Keat
Keyword(s):  
Thermal Conductivity ◽  
Density Functional Theory ◽  
High Temperature ◽  
Seebeck Coefficient ◽  
Temperature Dependence ◽  
Band Gap ◽  
Thermoelectric Properties ◽  
Density Functional ◽  
Electronic Band ◽  
Functional Theory

The electronic structure and thermoelectric properties of CaMnO3 doped with 8% and 17% f block element Sm using first principles calculations and semi-classic Boltzmann theory were presented in this paper. The G-type AFM phase is most stable among five phases for CaMnO3, however, with 8% and 17% Sm doping, these compounds became nonmagnetic phases. CaMnO3 calculated electronic band structure shows an indirect band gap of 0.523 eV, which is underestimated by the density functional theory (DFT) calculations but the band gap explains the semiconducting behavior. However, with 8% and 17% Sm doping, the electronic bandstructure of these compounds exhibit metallic behavior, with Sm and Mn 3d electrons contributing to conduction band, increasing the magnitude of conductivity for doped compounds. All temperature dependence Seebeck coefficient plots show n-typed conduction for all compound with reduced magnitude of Seebeck coefficient for doped compounds. The temperature dependence thermal conductivity plot shows overall thermal conductivity is reduced in Sm doped compound. CaMnO3 with 17% Sm doping exhibit much higher ZT of 0.32 at 800 K showing enhanced thermoelectric properties at high temperature and suitability or high temperature energy conversion devices.

Application of TEM to Deformation, Wear, and Fracture of Ceramics

1974 ◽  
Vol 32 ◽  
pp. 472-473
Author(s):  
B. J. Hockey
Keyword(s):  
Wear Resistance ◽  
High Temperature ◽  
Mechanical Behavior ◽  
Brittle Materials ◽  
High Temperature Strength ◽  
Wide Range ◽  
Corrosive Environments ◽  
Further Development

Ceramics, such as Al2O3 and SiC have numerous current and potential uses in applications where high temperature strength, hardness, and wear resistance are required often in corrosive environments. These materials are, however, highly anisotropic and brittle, so that their mechanical behavior is often unpredictable. The further development of these materials will require a better understanding of the basic mechanisms controlling deformation, wear, and fracture.The purpose of this talk is to describe applications of TEM to the study of the deformation, wear, and fracture of Al2O3. Similar studies are currently being conducted on SiC and the techniques involved should be applicable to a wide range of hard, brittle materials.

TEM study of boron additions to cobalt aluminide

1988 ◽  
Vol 46 ◽  
pp. 546-547
Author(s):  
Gerald B. Feldewerth
Keyword(s):  
High Temperature ◽  
Turbine Engines ◽  
Major Drawback ◽  
University Of Missouri ◽  
Specific Strength ◽  
Aerospace Applications ◽  
Wide Range ◽  
Ordered Alloys ◽  
The University ◽  
Very High

In recent years an increasing emphasis has been placed on the study of high temperature intermetallic compounds for possible aerospace applications. One group of interest is the B2 aiuminides. This group of intermetaliics has a very high melting temperature, good high temperature, and excellent specific strength. These qualities make it a candidate for applications such as turbine engines. The B2 aiuminides exist over a wide range of compositions and also have a large solubility for third element substitutional additions, which may allow alloying additions to overcome their major drawback, their brittle nature.One B2 aluminide currently being studied is cobalt aluminide. Optical microscopy of CoAl alloys produced at the University of Missouri-Rolla showed a dramatic decrease in the grain size which affects the yield strength and flow stress of long range ordered alloys, and a change in the grain shape with the addition of 0.5 % boron.

Efficient Prediction of Structural and Electronic Properties of Hybrid 2D Materials Using DFT and Machine Learning

2018 ◽  
Author(s):  
Sherif Tawfik ◽  
Olexandr Isayev ◽  
Catherine Stampfl ◽  
Joseph Shapter ◽  
David Winkler ◽  
...  
Keyword(s):  
Machine Learning ◽  
Band Gap ◽  
Density Functional ◽  
2D Materials ◽  
Van Der Waals ◽  
Building Blocks ◽  
Machine Learning Techniques ◽  
Interlayer Distance ◽  
Computational Screening ◽  
Wide Range

Materials constructed from different van der Waals two-dimensional (2D) heterostructures offer a wide range of benefits, but these systems have been little studied because of their experimental and computational complextiy, and because of the very large number of possible combinations of 2D building blocks. The simulation of the interface between two different 2D materials is computationally challenging due to the lattice mismatch problem, which sometimes necessitates the creation of very large simulation cells for performing density-functional theory (DFT) calculations. Here we use a combination of DFT, linear regression and machine learning techniques in order to rapidly determine the interlayer distance between two different 2D heterostructures that are stacked in a bilayer heterostructure, as well as the band gap of the bilayer. Our work provides an excellent proof of concept by quickly and accurately predicting a structural property (the interlayer distance) and an electronic property (the band gap) for a large number of hybrid 2D materials. This work paves the way for rapid computational screening of the vast parameter space of van der Waals heterostructures to identify new hybrid materials with useful and interesting properties.

PLATINUM

Alloy Digest ◽  
1970 ◽  
Vol 19 (11) ◽  
Keyword(s):  
Corrosion Resistance ◽  
High Temperature ◽  
Heat Treating ◽  
Industrial Applications ◽  
High Melting ◽  
High Melting Point ◽  
White Metal ◽  
Temperature Performance ◽  
Wide Range ◽  
Corrosion And Oxidation

Abstract PLATINUM is a soft, ductile, white metal which can be readily worked either hot or cold. It has a wide range of industrial applications because of its excellent corrosion and oxidation resistance and its high melting point. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Pt-1. Producer or source: Matthey Bishop Inc..

ACI TYPE HN

Alloy Digest ◽  
1982 ◽  
Vol 31 (6) ◽  
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
High Temperature ◽  
Steel Casting ◽  
Nickel Content ◽  
Heat Treating ◽  
High Temperature Corrosion ◽  
Temperature Performance ◽  
Wide Range ◽  
Iron Chromium

Abstract Type HN is an iron-chromium-nickel alloy containing sufficient chromium for good high-temperature corrosion resistance and with nickel content in excess of the chromium. This alloy has properties somewhat similar to the more widely used ACI Type HT alloy but with better ductility. Type HN is used for highly stressed components in the 1800-2000 F temperature range. It is used in the aircraft, automotive, petroleum, petrochemical and power industries for a wide range of components and parts. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as creep. It also includes information on high temperature performance and corrosion resistance as well as casting, heat treating, machining, and joining. Filing Code: SS-410. Producer or source: Various stainless steel casting companies.

Partially Anion-Ordered Cerium Niobium Oxynitride Perovskite Phase with a Small Band Gap

2021 ◽  
Author(s):  
Zonghao Shen ◽  
Ji Wu ◽  
Matthew W. Shorvon ◽  
Guillaume Cazaux ◽  
Stephen C. Parker ◽  
...  
Keyword(s):  
Band Gap ◽  
Perovskite Phase ◽  
Small Band

scholarly journals The Band-Gap Studies of Short-Period CdO/MgO Superlattices

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Ewa Przeździecka ◽  
P. Strąk ◽  
A. Wierzbicka ◽  
A. Adhikari ◽  
A. Lysak ◽  
...  
Keyword(s):  
Band Gap ◽  
Layer Thickness ◽  
Energy Gap ◽  
Band Gaps ◽  
Short Period ◽  
Wide Range ◽  
Salt Structure ◽  
Short Period Superlattices ◽  
Direct Band ◽  
Sublayer Thickness

AbstractTrends in the behavior of band gaps in short-period superlattices (SLs) composed of CdO and MgO layers were analyzed experimentally and theoretically for several thicknesses of CdO sublayers. The optical properties of the SLs were investigated by means of transmittance measurements at room temperature in the wavelength range 200–700 nm. The direct band gap of {CdO/MgO} SLs were tuned from 2.6 to 6 eV by varying the thickness of CdO from 1 to 12 monolayers while maintaining the same MgO layer thickness of 4 monolayers. Obtained values of direct and indirect band gaps are higher than those theoretically calculated by an ab initio method, but follow the same trend. X-ray measurements confirmed the presence of a rock salt structure in the SLs. Two oriented structures (111 and 100) grown on c- and r-oriented sapphire substrates were obtained. The measured lattice parameters increase with CdO layer thickness, and the experimental data are in agreement with the calculated results. This new kind of SL structure may be suitable for use in visible, UV and deep UV optoelectronics, especially because the energy gap can be precisely controlled over a wide range by modulating the sublayer thickness in the superlattices.

The Influence of Bi2O3 on SiO2-Al2O3-B2O3-RO Glass Propertiesarts

2014 ◽  
Vol 887-888 ◽  
pp. 86-89
Author(s):  
Ying Liang Tian ◽  
Jing Zhang ◽  
Shi Bing Sun ◽  
Ji Ye Fan
Keyword(s):  
Electrical Resistivity ◽  
High Temperature ◽  
Expansion Coefficient ◽  
Bismuth Oxide ◽  
Sintering Temperature ◽  
Oxide Content ◽  
Basic Composition ◽  
Wide Range ◽  
Melt Annealing ◽  
Annealing Method

In the paper, regarded SiO2-Al2O3-B2O3-RO system as basic composition, high-temperature glass glaze was prepared successfully by using Bi2O3 in place of Al2O3, and traditional melt annealing method was adopted .The influence of Bi2O3 on expansion coefficient, sintering temperature, electrical resistivity was investigated by DIL-2008, SJY sintering imager, Keythley2410. The results show that the sintering temperature of glass glaze has a wide range, which can reach 270°C, so it is easy to sinter; with the increasing of bismuth oxide content, expansion coefficient of glass glaze gradually increases, whereas sintering temperature and electrical resistivity continuously decreases.

Re-examination of the High-Temperature Resistivity Anomaly in(Cr0.01V0.99)2O3

1974 ◽  
Vol 32 (1) ◽  
pp. 13-15 ◽  
Author(s):  
J. M. Honig ◽  
G. V. Chandrashekhar ◽  
A. P. B. Sinha
Keyword(s):  
High Temperature ◽  
Temperature Resistivity
Sign in / Sign up

Export Citation Format

Share Document