Enhanced thermoelectric properties of nano-SiC dispersed NaCo2O4 composites

2019 ◽  
Vol 12 (02) ◽  
pp. 1950009 ◽  
Author(s):  
Wei Zhang ◽  
Kongjun Zhu ◽  
Jinsong Liu ◽  
Jing Wang ◽  
Kang Yan ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
High Temperature ◽  
Cobalt Oxides ◽  
Solid State Method ◽  
Sic Nanoparticles ◽  
Energy Filtering ◽  
State Method ◽  
Filtering Effect

Sodium cobalt oxides (NaCo2O[Formula: see text] have attracted considerable attention as promising high-temperature thermoelectric (TE) candidates. In this study, we choose nano-SiC as an inclusion to synthesize NaCo2O4-based composites using the solid-state method. The crystal structure and TE properties for nano-SiC dispersed NaCo2O4 composites with different SiC contents are discussed. The results indicate that the SiC nanoparticles can suppress the grain growth and form many new grain boundaries and interface to reduce thermal conductivity observably. Moreover, the electrical conductivity and Seebeck coefficient can be improved by the energy filtering effect. Therefore, the maximum ZT of 0.122 is obtained from the samples with 0.2[Formula: see text]vol.% nano-SiC, approximately two times higher than that of pure NaCo2O4. This study provides a facile strategy to synthesize nanocomposites to enhance TE performance efficiently.

Photoluminescence Properties of Ca3Si2O7: Pr3+ Orange-Red Phosphors Prepared by High-Temperature Solid-State Method

2018 ◽  
Vol 73 (6) ◽  
pp. 555-558 ◽  
Author(s):  
Zhi-Qing Peng ◽  
Rong Chen ◽  
Wen-Lin Feng
Keyword(s):  
Crystal Structure ◽  
High Temperature ◽  
Solid State ◽  
Solid State Method ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Red Phosphors ◽  
Typical Sample ◽  
State Method ◽  
Xrd Patterns

AbstractNovel luminescent materials Ca3-xSi2O7: xPr3+ were successfully prepared by the high-temperature solid-state method. The crystal structure, morphology, and optical spectrum were characterised by X-ray diffraction (XRD), scanning electron microscopy (SEM), and spectroscopy, respectively. The XRD patterns of the samples indicate that the crystal structure is monoclinic symmetry. The SEM shows that the selected sample has good crystallinity although its appearance is irregular and scalelike. The peak of the excitation spectrum of the sample is located at around 449 nm, corresponding to 3H4→3P2 transition of Pr3+. The peak of the emission spectrum of the sample is situated at around 612 nm which is attributed to 3P0→3H6 transition of Pr3+, and the colour is orange-red. The optimum concentration for Pr3+ replaced Ca2+ sites in Ca3Si2O7: Pr3+ is 0.75 mol%. The lifetime (8.48 μs) of a typical sample (Ca2.9925Pr0.0075)Si2O7 is obtained. It reveals that orange-red phosphors Ca3-xSi2O7: xPr3+ possess remarkable optical properties and can be used in white light emitting devices.

Crystal structure, luminescence properties, energy transfer, tunable occupation and thermal properties of a novel color-tunable phosphor NaBa1−zSrzB9O15:xCe3+,yMn2+

2018 ◽  
Vol 47 (39) ◽  
pp. 13913-13925 ◽  
Author(s):  
Qi Bao ◽  
Zhijun Wang ◽  
Jiang Sun ◽  
Zhipeng Wang ◽  
Xiangyu Meng ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Energy Transfer ◽  
Thermal Properties ◽  
High Temperature ◽  
Solid State ◽  
Luminescence Properties ◽  
Solid State Method ◽  
Color Tunable ◽  
State Method

A series of color-tunable NaBa1−zSrzB9O15:Ce3+,Mn2+ phosphors were synthesized by a high temperature solid state method.

scholarly journals Synthesis, Crystal Structure, and Electrical Properties of a New Molybdylarsenate LiNa5K3Mo11As3O45

2014 ◽  
Vol 2014 ◽  
pp. 1-9
Author(s):  
Hamadi Hamza ◽  
Mohamed Faouzi Zid ◽  
Ahmed Driss
Keyword(s):  
Crystal Structure ◽  
Electrical Conductivity ◽  
Solid State ◽  
Inorganic Compound ◽  
X Ray Diffraction ◽  
Solid State Method ◽  
One Dimensional ◽  
X Ray ◽  
Triclinic System ◽  
State Method

LiNa5K3Mo11As3O45 is a new inorganic compound. It was synthesized by a solid state method. The crystal structure has been studied by single crystal X-ray analysis. The R-values reached 2.8%. The title compound crystallizes in the triclinic system, space group P-1, with a = 10.550 (2) Å, b = 11.723 (2) Å, c = 17.469 (3) Å, α = 102.35 (3)°, β = 87.61 (2)°, and γ = 111.03 (3)°. The anionic unit [Mo11As3O45]9− is formed by nine MoO6 octahedra, two MoO5 trigonal bipyramids, and three AsO4 tetrahedra. The association of [Mo11As3O45]9− units, running along [010], leads to a one-dimensional framework. Li, K, and Na are located in the space surrounding the anionic ribbons. This material was characterized by SEM microscopy, IR spectroscopy, and powder X-ray diffraction. The electrical conductivity was investigated from 528 K to 673 K by impedance complex followed by DSC spectroscopy.

Preparation and investigation of Dy3+/Tm3+ doped NaGd(MoO4)2 with thermal-stable and tunable white light emitting for LED applications

CrystEngComm ◽  
2022 ◽  
Author(s):  
Xiaochen Yu ◽  
Yinlin Jiang ◽  
Xiaojie Li ◽  
Zeyu Song ◽  
Xu Zhang ◽  
...  
Keyword(s):  
Crystal Structure ◽  
High Temperature ◽  
Solid State ◽  
Band Structure ◽  
Elemental Composition ◽  
White Light ◽  
Solid State Method ◽  
Light Emitting ◽  
State Method ◽  
Thermal Stable

In this work, a series of Dy3+-doped, Tm3+-doped and Dy3+/Tm3+-codoped NaGd(MoO4)2 (NGM) were successfully prepared via high-temperature solid-state method. The crystal structure, band structure, elemental composition, and photoluminescence (PL) properties...

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.

Photoluminescence Properties of K1-xSr4(BO3)3∶xPr3+ Phosphors Prepared by High-Temperature Solid-State Method

2017 ◽  
Vol 37 (5) ◽  
pp. 0516001
Author(s):  
马诗章 Ma Shizhang ◽  
冯文林 Feng Wenlin ◽  
彭志清 Peng Zhiqing
Keyword(s):  
High Temperature ◽  
Solid State ◽  
Photoluminescence Properties ◽  
Solid State Method ◽  
State Method

scholarly journals Silver vacancy concentration engineering leading to the ultralow lattice thermal conductivity and improved thermoelectric performance of Ag1-xInTe2

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Yaqiong Zhong ◽  
Yong Luo ◽  
Xie Li ◽  
Jiaolin Cui
Keyword(s):  
Crystal Structure ◽  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Point Defects ◽  
Lattice Thermal Conductivity ◽  
Vacancy Concentration ◽  
Antisite Defect ◽  
Thermoelectric Performance ◽  
Callaway Model

AbstractAgInTe2 compound has not received enough recognition in thermoelectrics, possibly due to the fact that the presence of Te vacancy (VTe) and antisite defect of In at Ag site (InAg) degrades its electrical conductivity. In this work, we prepared the Ag1-xInTe2 compounds with substoichiometric amounts of Ag and observed an ultralow lattice thermal conductivity (κL = 0.1 Wm−1K−1) for the sample at x = 0.15 and 814 K. This leads to more than 2-fold enhancement in the ZT value (ZT = 0.62) compared to the pristine AgInTe2. In addition, we have traced the origin of the untralow κL using the Callaway model. The results attained in this work suggest that the engineering of the silver vacancy (VAg) concentration is still an effective way to manipulate the thermoelectric performance of AgInTe2, realized by the increased point defects and modified crystal structure distortion as the VAg concentration increases.

scholarly journals Enhanced thermoelectric performance of Bi–Sb–Te/Sb2O3 nanocomposites by energy filtering effect

2018 ◽  
Vol 6 (43) ◽  
pp. 21341-21349 ◽  
Author(s):  
Amir Pakdel ◽  
Quansheng Guo ◽  
Valeria Nicolosi ◽  
Takao Mori
Keyword(s):  
Thermal Conductivity ◽  
Seebeck Coefficient ◽  
Thermoelectric Performance ◽  
Energy Filtering ◽  
Filtering Effect

24 month high-ZT stability of Bi0.5Sb1.5Te3/Sb2O3 nanocomposites that demonstrate simultaneous Seebeck coefficient enhancement and thermal conductivity decline through energy filtering effect.

High-temperature thermoelectric properties of n-type BayNixCo4−xSb12

2001 ◽  
Vol 16 (12) ◽  
pp. 3343-3346 ◽  
Author(s):  
X. F. Tang ◽  
L. M. Zhang ◽  
R. Z. Yuan ◽  
L. D. Chen ◽  
T. Goto ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
High Temperature ◽  
Seebeck Coefficient ◽  
Thermoelectric Properties ◽  
Electron Concentration ◽  
Lattice Thermal Conductivity ◽  
Filling Fraction ◽  
Ni Content ◽  
Increasing Temperature

Effects of Ba filling fraction and Ni content on the thermoelectric properties of n-type BayNixCo4−xSb12 (x = 0−0.1, y = 0−0.4) were investigated at temperature range of 300 to 900 K. Thermal conductivity decreased with increasing Ba filling fraction and temperature. When y was fixed at 0.3, thermal conductivity decreased with increasing Ni content and reached a minimum value at about x = 0.05. Lattice thermal conductivity decreased with increasing Ni content, monotonously (y ≤ 0.1). Electron concentration and electrical conductivity increased with increasing Ba filling fraction and Ni content. Seebeck coefficient increased with increasing temperature and decreased with increasing Ba filling fraction and Ni content. The maximum ZT value of 1.25 was obtained at about 900 K for n-type Ba0.3Ni0.05Co3.95Sb12.

The Effect of Sintering Temperature to the Properties of Zinc Oxide

2013 ◽  
Vol 795 ◽  
pp. 419-423 ◽  
Author(s):  
J.H. Lim ◽  
C.K. Yeoh ◽  
Pei Leng Teh ◽  
W.M. Arif ◽  
A. Chik
Keyword(s):  
Thermal Conductivity ◽  
Zinc Oxide ◽  
Thermal Properties ◽  
Solid State ◽  
Sintering Temperature ◽  
Solid State Method ◽  
Influence Of Temperature ◽  
Temperature Range ◽  
Influence Of Temperature On ◽  
State Method

In this paper, different sintering temperature used to study the influence of temperature on the structural and thermal properties of zinc oxide (ZnO). On this research, the sample was prepared by solid-state method for zinc oxide (ZnO) at different sintering temperature which was 700°C, 800°C and 900°C. It was observed that the density of bulk ZnO that sintering at 900°C had the higher value of density 5.03 g/cm3. The microhardness of the bulk ZnO had a higher measurement 397.3 Hv after sintered at 900°C. ZnO that sintering at 900°C had been observed that had thermal conductivity 1.1611W/cm-K in the sintering temperature range 700°C to 900°C.

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