Superconductivity, Seebeck coefficient, and band structure transformation in Y1−x CaxBa2Cu3−x CoxOy (x=0–0.3)

1999 ◽  
Vol 41 (8) ◽  
pp. 1248-1255 ◽  
Author(s):  
M. V. Elizarova ◽  
V. É. Gasumyants
Keyword(s):  
Band Structure ◽  
Seebeck Coefficient ◽  
Structure Transformation

Band Structure and Thermoelectric Properties of Ni(x)Zn(1-x)Fe2O4

2021 ◽  
Vol 317 ◽  
pp. 28-34
Author(s):  
Joon Hoong Lim
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Band Structure ◽  
Seebeck Coefficient ◽  
Band Gap ◽  
Thermoelectric Properties ◽  
Xrd Analysis ◽  
Valence Band Maximum ◽  
Solid State Method ◽  
Ni Content

Thermoelectric materials has made a great potential in sustainable energy industries, which enable the energy conversion from heat to electricity. The band structure and thermoelectric properties of Ni(x)Zn(1-x)Fe2O4 have been investigated. The bulk pellets were prepared from analytical grade ZnO, NiO and Fe2O3 powder using solid-state method. It was possible to obtain high thermoelectric properties of Ni(x)Zn(1-x)Fe2O4 by controlling the ratios of dopants and the sintering temperature. XRD analysis showed that the fabricated samples have a single phase formation of cubic spinel structure. The thermoelectric properties of Ni(x)Zn(1-x)Fe2O4 pellets improved with increasing Ni. The electrical conductivity of Ni(x)Zn(1-x)Fe2O4 pellets decreased with increasing Ni content. The electrical conductivity of Ni(x)Zn(1-x)Fe2O4 (x = 0.0) is (0.515 x10-3 Scm-1). The band structure shows that ZnxCu1-xFe2O4 is an indirect band gap material with the valence band maximum (VBM) at M and conduction band minimum (CBM) at A. The band gap of Ni(x)Zn(1-x)Fe2O4 increased with increasing Ni content. The increasing band gap correlated with the lower electrical conductivity. The thermal conductivity of Ni(x)Zn(1-x)Fe2O4 pellets decreased with increasing Ni content. The presence of Ni served to decrease thermal conductivity by 8 Wm-1K-1 over pure samples. The magnitude of the Seebeck coefficient for Ni(x)Zn(1-x)Fe2O4 pellets increased with increasing amounts of Ni. The figure of merit for Ni(x)Zn(1-x)Fe2O4 pellets and thin films was improved by increasing Ni due to its high Seebeck coefficient and low thermal conductivity.

Influence of the band structure of BiSb alloy on the magneto-Seebeck coefficient

2008 ◽  
Vol 104 (5) ◽  
pp. 053714 ◽  
Author(s):  
Takayuki Teramoto ◽  
Takashi Komine ◽  
Shinji Yamamoto ◽  
Masahiro Kuraishi ◽  
Ryuji Sugita ◽  
...  
Keyword(s):  
Band Structure ◽  
Seebeck Coefficient

Band structure modification of the thermoelectric Heusler-phase TiFe2Sn via Mn substitution

2017 ◽  
Vol 19 (28) ◽  
pp. 18273-18278 ◽  
Author(s):  
Tianhua Zou ◽  
Tiantian Jia ◽  
Wenjie Xie ◽  
Yongsheng Zhang ◽  
Marc Widenmeyer ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Band Structure ◽  
Seebeck Coefficient ◽  
Fermi Level ◽  
Density Of States ◽  
Effective Strategy ◽  
Structure Modification ◽  
Electronic Density ◽  
Heusler Phase ◽  
Mn Substitution

Doping (or substitution)-induced modification of the electronic structure to increase the electronic density of states (eDOS) near the Fermi level is considered as an effective strategy to enhance the Seebeck coefficient, and may consequently boost the thermoelectric performance.

Optical and thermoelectric response of RhTiSb half-Heusler

2019 ◽  
Vol 33 (22) ◽  
pp. 1950247 ◽  
Author(s):  
Besbes Anissa ◽  
Djelti Radouan ◽  
Bestani Benaouda
Keyword(s):  
Refractive Index ◽  
Band Structure ◽  
Absorption Coefficient ◽  
Seebeck Coefficient ◽  
Dielectric Function ◽  
Figure Of Merit ◽  
Large Range ◽  
Ultraviolet Region ◽  
Optical Parameters ◽  
Boltzmann Transport

Structural, electronic, optical and thermoelectric response of the cubic RhTiSb compound is reported using TB-mBJ potential. The calculated results for the band structure and DOS confirm that the RhTiSb is a nonmagnetic (NM) semiconductor with an indirect bandgap of 0.71 eV. The main optical parameters such as dielectric function, absorption coefficient, refractive index and optical reflectivity were estimated for emission upto 14 eV. The RhTiSb half-Heusler exhibits a maximum absorption in the visible and ultraviolet region. By using the Boltzmann transport equations as incorporated in BoltzTraP code, the thermoelectric characteristics were calculated. The main properties which describe the aptitude of material in thermoelectric environment such as Seebeck coefficient and figure of merit were calculated. The high values of figure-of-merit (ZT [Formula: see text] 0.7) were observed in large range of temperature indicating that RhTiSb have a good thermoelectric performance.

New Conjugated Polymers Derived from Carbazole as Thermoelectric Materials

2005 ◽  
Vol 871 ◽  
Author(s):  
Isabelle Lévesque ◽  
Xing Gao ◽  
Christopher I. Ratcliffe ◽  
Dennis D. Klug ◽  
John S. Tse ◽  
...  
Keyword(s):  
Band Structure ◽  
Seebeck Coefficient ◽  
Conjugated Polymers ◽  
Power Factor ◽  
Thermoelectric Materials ◽  
Doping Level ◽  
Room Temperature ◽  
Polymer Structure ◽  
Band Structure Calculations ◽  
Structure Calculations

AbstractNovel poly(3,6-hexyl-2,7-N-octylcarbazole) derivatives and poly(diindolocarbazole)s were synthesized. Optical, electrochemical, electrical and thermoelectric properties were investigated. Band structure calculations were used to predict which polymers were promising as thermoelectric materials. The best combination of Seebeck coefficient and conductivity (power factor) was 9,4 x10-8 Wm-1K-2 with a copolymer of carbazole and thiophene. This corresponds to a ZT at room temperature of 0.0003. Optimization of the polymer structure and doping level should lead to an increased ZT.

Influence of trigonal deformation on band structure and Seebeck coefficient of tellurium

2019 ◽  
Vol 135 ◽  
pp. 109114 ◽  
Author(s):  
J.C. Han ◽  
C.Y. Wu ◽  
L. Sun ◽  
H.R. Gong ◽  
X. Gong
Keyword(s):  
Band Structure ◽  
Seebeck Coefficient

Thermoelectric Properties of Bi1-xSbx Nanowire Arrays

2001 ◽  
Vol 691 ◽  
Author(s):  
Yu-Ming Lin ◽  
Stephen B. Cronin ◽  
Oded Rabin ◽  
Jackie Y. Ying ◽  
Mildred S. Dresselhaus
Keyword(s):  
Theoretical Model ◽  
Band Structure ◽  
Seebeck Coefficient ◽  
Transport Property ◽  
Field Dependence ◽  
Nanowire Arrays ◽  
Temperature Dependent ◽  
Thermoelectric Transport ◽  
Alloy Nanowires ◽  
Different Diameters

ABSTRACTWe present here a thermoelectric transport property study of Bi1−xSbx alloy nanowires embedded in a dielectric matrix. Temperature-dependent resistance measurements exhibit nonmonotonic trends as the antimony mole fraction (x) increases, and a theoretical model is presented to explain the features that are related to the unusual band structure of Bi1−xSbx systems. Seebeck coefficient measurements are performed on nanowires with different diameters and compositions, showing enhanced thermopower over bulk Bi. The magneto-Seebeck coefficient of these nanowires also exhibits an unusual field dependence that is absent in bulk samples.

Enhancement of the thermoelectric performance of bulk SnTe alloys via the synergistic effect of band structure modification and chemical bond softening

2017 ◽  
Vol 5 (27) ◽  
pp. 14165-14173 ◽  
Author(s):  
Hongchao Wang ◽  
Junphil Hwang ◽  
Chao Zhang ◽  
Teng Wang ◽  
Wenbin Su ◽  
...  
Keyword(s):  
Synergistic Effect ◽  
Band Structure ◽  
Seebeck Coefficient ◽  
Effective Mass ◽  
Chemical Bond ◽  
Resonance Level ◽  
Thermoelectric Performance ◽  
Energy Separation ◽  
Structure Modification ◽  
Bond Softening

Seebeck coefficient of SnTe is largely enhanced by large band effective mass or decrease of energy separation through synergistic effect including resonance level and band convergence.

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