Study and Design for High Thermoelectric Properties for AgxTeyTlz Compound with First Principle Band Calculation

2010 ◽  
Vol 74 ◽  
pp. 15-21
Author(s):  
Hiroki Funashima ◽  
Noriaki Hamada
Keyword(s):  
Electronic Band Structure ◽  
Local Density ◽  
Band Structure Calculation ◽  
Full Potential ◽  
First Principles Calculations ◽  
Electronic Band ◽  
Augmented Plane Wave ◽  
Plane Wave Method ◽  
Augmented Plane Wave Method ◽  
Linearized Augmented Plane Wave

Recently it was reported that AgxTeyTz shows extremely low thermal conductivity, and high power generating efficiency as a thermoelectric conversion material[1]. We evaluate the seebeck coefficient on basis of the first principles calculations. The electronic band structure calculation is performed using all-electron full-potential linearized augmented plane-wave method(FLAPW) within the local density approximation(LDA). The seebeck coefficent is analyzed by Bloch-Boltzmann equation. In this paper, we find that AgTeTl and AgTe2Tl3 are better thermoelectric material among AgxTeyTlz.

Optical Properties of the Strained Layer Superlattices (GaAs)6/(GaP)m(001) (m=2, 4 and 6)

2009 ◽  
Vol 609 ◽  
pp. 41-48 ◽  
Author(s):  
Ali Hamidani ◽  
B. Bennecer
Keyword(s):  
Optical Properties ◽  
Local Density ◽  
Full Potential ◽  
First Principles Calculations ◽  
Augmented Plane Wave ◽  
Strained Layer ◽  
Plane Wave Method ◽  
Augmented Plane Wave Method ◽  
Strained Layer Superlattices ◽  
Linearized Augmented Plane Wave

First principles calculations, by means of the full-potential linearized augmented plane wave method within the local density approximation, were carried out for the optical properties of the strained layer superlattices (GaAs)6/(GaP)m(001) (m=2, 4 and 6). The calculated imaginary part of the dielectric function agrees well with the available experimental data. The assignment of the structures and the peaks in the optical spectra and band structure transitions are investigated in detail. Our results indicate that the anisotropy in these materials is mostly due to the tensile strain in the GaP layers.

Research on Topological Insulating Materials Induced by Uniaxial Strains with Properties of Insulating Materials

2013 ◽  
Vol 675 ◽  
pp. 180-183
Author(s):  
Hong Pei Han ◽  
Xin Ping Dong
Keyword(s):  
Electronic Band Structure ◽  
Full Potential ◽  
Electronic Band ◽  
Insulating Materials ◽  
Augmented Plane Wave ◽  
Plane Wave Method ◽  
Low Energy Consumption ◽  
Temperature Application ◽  
Insulating Phase ◽  
Linearized Augmented Plane Wave

A series of calculations are carried out to investigate systematically the electronic band structure of bulk HgTe under uniaxial strains with the relaxed-volume by means of the full potential linearized augmented plane-wave method. Our results show that there is a topological insulating phase induced by proper uniaxial strains, which is consistent with previous theoretical and experimental results. Interestingly, the strain-induced band gap is large up to 0.21 and 0.17 eV in expansion and compression along c-direction, respectively. It is indicated that the bulk HgTe under proper uniaxial strains would be possibly made the room temperature application for material engineering with low energy consumption.

The Lattice Distortion-Induced Topological Insulating Material

2013 ◽  
Vol 676 ◽  
pp. 13-16
Author(s):  
Hong Pei Han
Keyword(s):  
Electronic Band Structure ◽  
Full Potential ◽  
Electronic Band ◽  
Augmented Plane Wave ◽  
Plane Wave Method ◽  
Low Energy Consumption ◽  
Temperature Application ◽  
Lattice Distortions ◽  
Insulating Phase ◽  
Linearized Augmented Plane Wave

We have carried out a series of calculations to investigate the electronic band structure of bulk HgTe strained along c-direction with the constant-volume by means of the full potential linearized augmented plane-wave method. Our results show that there is a topological insulating phase induced by the lattice distortions, which is in agreement with previous theoretical and experimental results. Importantly, the distortion-induced band gap is large up to 0.19 eV in either expansion or compression along c-direction. It is indicated that the bulk HgTe under proper lattice distortions would be possibly made the room temperature application for material engineering with low energy consumption.

FIRST-PRINCIPLE THEORETICAL STUDY ON THE CALCIUM FERRITE-TYPE LiMn2O4

2010 ◽  
Vol 03 (02) ◽  
pp. 93-96 ◽  
Author(s):  
MEILING LI ◽  
YUE ZHANG ◽  
LIN LI
Keyword(s):  
Magnetic Moments ◽  
Mixed Valence ◽  
Calcium Ferrite ◽  
Full Potential ◽  
Augmented Plane Wave ◽  
Plane Wave Method ◽  
Augmented Plane Wave Method ◽  
Structural And Electronic Properties ◽  
Mixed Valence Compound ◽  
Linearized Augmented Plane Wave

The structural and electronic properties of the calcium ferrite-type LiMn 2 O 4 were studied using the full-potential linearized augmented plane wave method. The results showed that LiMn 2 O 4 was an antiferromagnetic semiconductor from GGA+U calculations, similar to the experimental report of Li 0.92 Mn 2 O 4. The spin magnetic moments and density of states of Mn atoms showed that LiMn 2 O 4 was a mixed-valence compound with Mn 3+ and Mn 4+ cations randomly distributed amongst the octahedral sites.

Design and evaluation of n-type Si1-xGex as a thermoelectric-conversion material

2007 ◽  
Vol 1044 ◽  
Author(s):  
Tomohiro Imai ◽  
Tsutomu Iida ◽  
Yuki Miyata ◽  
Takashi Itoh ◽  
Hiroki Funashima ◽  
...  
Keyword(s):  
Seebeck Coefficient ◽  
Thermoelectric Power ◽  
Electronic Band Structure ◽  
Local Density ◽  
Band Structure Calculation ◽  
Full Potential ◽  
Electronic Band ◽  
Thermoelectric Conversion ◽  
High Seebeck Coefficient ◽  
Flapw Method

AbstractSi1-xGex alloys show the high power generating efficiency as a thermoelectric- conversion material. We evaluate the thermoelectric power of the n-type SiGe system on the basis of the first principles calculations. The electronic-band-structure calculation is performed using all-electron full-potential linearized augmented-plane-wave (FLAPW) method within the local density approximation (LDA). The Seebeck coefficient is analyzed by the Bloch-Boltzmann equation. We find that the ordered rhombohedral SiGe has high Seebeck coefficient in comparison with zincblende SiGe. The efficiency of the thermoelectric power in Si1-xGex is gained by the local atomic configuration rather than the Ge concentration.

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