scholarly journals Thermoelectric Properties of Cu2Se Synthesized by Hydrothermal Method and Densified by SPS Technique

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3650
Author(s):  
Paweł Nieroda ◽  
Anna Kusior ◽  
Juliusz Leszczyński ◽  
Paweł Rutkowski ◽  
Andrzej Koleżyński
Keyword(s):  
Electron Microscopy ◽  
Hydrothermal Method ◽  
Thermoelectric Properties ◽  
Composition Studies ◽  
X Ray Diffraction ◽  
Plasma Sintering ◽  
Transmission Electron ◽  
Thermoelectric Transport Properties ◽  
Spark Plasma ◽  
Very High

The aim of the work was to obtain copper (I) selenide Cu2Se material with excellent thermoelectric properties, synthesized using the hydrothermal method and densified by the spark plasma sintering (SPS) method. Chemical and phase composition studies were carried out by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) methods. Measurements of thermoelectric transport properties, i.e., electrical conductivity, the Seebeck coefficient, and thermal conductivity in the temperature range from 300 to 965 K were carried out. Based on these results, the temperature dependence of the thermoelectric figure of merit ZT as a function of temperature was determined. The obtained, very high ZT parameter (ZT~1.75, T = 965 K) is one of the highest obtained so far for undoped Cu2Se.

Fullerene-Metal Composites: Phase Transformations During Milling and Sintering

2011 ◽  
Vol 172-174 ◽  
pp. 727-732 ◽  
Author(s):  
Ileana Irais Santana ◽  
Francisco Carlos Robles Hernandez ◽  
Vicente Garibay-Febles ◽  
Hector A. Calderon
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Phase Transformations ◽  
Mechanical Milling ◽  
X Ray Diffraction ◽  
Metal Composites ◽  
X Ray ◽  
Plasma Sintering ◽  
Transmission Electron ◽  
Spark Plasma

Composites of Fe-C60and Al C60produced by mechanical milling and sinterized by Spark Plasma Sintering are investigated with special attention to the mechanical properties of the products. The processing involves phase transformations of the fullerenes that are interesting to follow and characterize. This involves formation of tetragonal/rhombohedral diamond and carbides during sintering and milling. Transmission Electron Microscopy (TEM) and Raman Spectroscopy techniques are also used to confirm preliminary results of X Ray Diffraction (XRD) related to the formation of nanostructures i.e., grain size of the crystals during mechanical milling and after sintering, spatial distribution of phases and the different phases that are developed during processing.

Spark Plasma Sintering of PbTe Thermoelectric Bulk Materials With Small Grains

2008 ◽  
Author(s):  
Chia-Hung Kuo ◽  
Chii-Shyang Hwang ◽  
Jie-Ren Ku ◽  
Ming-Shan Jeng ◽  
Fang-Hei Tsau
Keyword(s):  
Electron Microscopy ◽  
Spark Plasma Sintering ◽  
X Ray Diffraction ◽  
Bulk Materials ◽  
Combination Process ◽  
Plasma Sintering ◽  
Transmission Electron ◽  
Spark Plasma ◽  
Diffraction Patterns ◽  
Microscopy Images

PbTe is a conventional thermoelectric material for thermoelectric generator at intermediate temperature. Small grain size effect has been reported to improve PbTe ZT values (figure of merit). We report a combination process of attrition milling and spark plasma sintering (SPS) for preparing PbTe bulk materials with small grain sizes. The PbTe powders were milled by attrition under 600 rpm for 6–96 h and followed by SPS process under the sintering temperature of 573–773 K, the heating rate of 100 K/min, and the sintering pressure of 50 MPa. The powders and bulk materials as-prepared were then studied by X-ray diffraction patterns, scanning electron microscopy images, and transmission electron microscopy images. Transport properties of polycrystalline PbTe bulks were evaluated through temperature dependent thermal conductivity measurements.

scholarly journals Microstructure and properties of nano-laminated Y3Si2C2 ceramics fabricated via in situ reaction by spark plasma sintering

2021 ◽  
Vol 10 (3) ◽  
pp. 578-586
Author(s):  
Lin-Kun Shi ◽  
Xiaobing Zhou ◽  
Jian-Qing Dai ◽  
Ke Chen ◽  
Zhengren Huang ◽  
...  
Keyword(s):  
Spark Plasma Sintering ◽  
Atomic Scale ◽  
Max Phase ◽  
X Ray Diffraction ◽  
Selected Area Electron Diffraction ◽  
Plasma Sintering ◽  
Transmission Electron ◽  
Spark Plasma ◽  
Diffraction Patterns

AbstractA nano-laminated Y3Si2C2 ceramic material was successfully synthesized via an in situ reaction between YH2 and SiC using spark plasma sintering technology. A MAX phase-like ternary layered structure of Y3Si2C2 was observed at the atomic-scale by high resolution transmission electron microscopy. The lattice parameters calculated from both X-ray diffraction and selected area electron diffraction patterns are in good agreement with the reported theoretical results. The nano-laminated fracture of kink boundaries, delamination, and slipping were observed at the tip of the Vickers indents. The elastic modulus and Vickers hardness of Y3Si2C2 ceramics (with 5.5 wt% Y2O3) sintered at 1500 °C were 156 and 6.4 GPa, respectively. The corresponding values of thermal and electrical conductivity were 13.7 W·m-1·K-1 and 6.3×105 S·m-1, respectively.

scholarly journals Perovskite CsPbBr3 Quantum Dots Prepared Using Discarded Lead–Acid Battery Recycled Waste

Energies ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 1117 ◽  
Author(s):  
Lung-Chien Chen ◽  
Ching-Ho Tien ◽  
Sin-Liang Ou ◽  
Kun-Yi Lee ◽  
Jianjun Tian ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Structural Characteristics ◽  
Film Surface ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Storage Batteries ◽  
Recycled Waste ◽  
Cspbbr3 Quantum Dots ◽  
Very High ◽  
Lead Acid

Perovskite CsPbBr3 quantum dot (CsPbBr3-QD) recovery was performed using lead scrap from lead storage batteries. The perovskite CsPbBr3-QD characteristics were analyzed using different PbO/recycled PbO2 ratios. Scanning electron microscopy (SEM) was used to observe the film surface morphology and cross-section. High-resolution transmission electron microscopy (HRTEM) and X-ray diffraction (XRD) were used to observe the perovskite CsPbBr3-QDs’ structural characteristics. A photoluminescence (PL) measurement system was used to analyze the optical properties. The results show that lead scrap from lead–acid batteries as a material for perovskite CsPbBr3-QD production can be successfully synthesized. This saves material and also proves that recycling is valuable. The proposed approach is helpful for future material shortages and materials not easily accessible. Although the efficiency is not very high, this process will be purified using recycled lead in the future to achieve higher quantum yield.

Effect of the Dwell Temperature on Spark Plasma Sintered CaCu3Ti4O12

2012 ◽  
Vol 727-728 ◽  
pp. 982-987
Author(s):  
E. de Carvalho ◽  
Marcelo Bertolete ◽  
Izabel Fernanda Machado ◽  
E.N.S. Muccillo
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Lattice Parameter ◽  
Solid State Reactions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Diffraction Patterns ◽  
Scanning Electron

Polycrystalline CaCu3Ti4O12 ceramics were prepared by solid state reactions by spark plasma sintering (SPS) technique. In this study, the effects of the dwell temperature on structural, microstructural and dielectric properties of CaCu3Ti4O12 ceramics have been investigated. Powder mixtures were calcined at 900°C for 18 h before SPS consolidation. The dwell temperatures were 850, 900, 915 and 930°C. Sintered pellets were characterized by X-ray diffraction, scanning electron microscopy and impedance spectroscopy. X-ray diffraction patterns show evidences of a single-phase perovskite-type structure. The calculated lattice parameter is 7.40 Å. The hydrostatic density increases slightly with increasing dwell temperature. Scanning electron microscopy observations revealed a heterogeneous microstructure for all samples. The dielectric loss remains constant over a wide temperature range. The obtained permittivity is approximately 103 at 1 kHz. The increase of the dwell temperature is found to produce a brittle ceramic.

THE GROWTH OF MnSi1.73 PREPARED BY SPARK PLASMA SINTERING

2004 ◽  
Vol 18 (01) ◽  
pp. 87-93 ◽  
Author(s):  
ZHIMIN WANG ◽  
YIDONG WU ◽  
YUANJIN HE
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Spark Plasma Sintering ◽  
X Ray Diffraction ◽  
Mechanical Pressure ◽  
Growth Processes ◽  
X Ray ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Scanning Electron

Crystals of MnSi 1.73 were prepared by Spark Plasma Sintering (SPS) technique, analyzed by X-ray diffraction (XRD), and invested by metalogragh and scanning electron microscopy (SEM). The growth processes of the samples were studied. It was found that the Mn–Si powders partly formed MnSi 1.73 crystals at 912–937 K under the mechanical pressure of 20 MPa in low vacuum (about 5.0 Pa), and fully formed MnSi 1.73 crystals after sintered at 1173 K for 15 minutes under 40 MPa.

scholarly journals Microstructure and properties of nano-laminated Y3Si2C2 ceramics fabricated via in situ reaction by spark plasma sintering

2020 ◽  
Author(s):  
Lin-Kun Shi ◽  
Xiaobing Zhou ◽  
Jian-Qing Dai ◽  
Ke Chen ◽  
Zhengren Huang ◽  
...  
Keyword(s):  
Spark Plasma Sintering ◽  
Atomic Scale ◽  
Max Phase ◽  
X Ray Diffraction ◽  
Selected Area Electron Diffraction ◽  
Plasma Sintering ◽  
Transmission Electron ◽  
Spark Plasma ◽  
Diffraction Patterns

Abstract A new nano-laminated Y3Si2C2 ceramic material, for the first time, was successfully synthesized via in situ reaction between YH2 and SiC by spark plasma sintering. A MAX phase-like ternary layered structure of Y3Si2C2 was observed at the atomic-scale by high resolution transmission electron microscopy. The lattice parameters calculated from both X-ray diffraction and selected area electron diffraction patterns are in good agreement with the reported theoretical results. The nano-laminated fracture of kink boundaries, delamination, and slipping was observed at the tip of the Vickers indent. The values of elastic modulus and Vickers hardness of the Y3Si2C2 ceramics sintered at 1500 °C were 156 and 6.4 GPa, respectively. The corresponding values of thermal and electrical conductivity were 13.7 W m-1 k-1 and 6.3 × 105 S m-1, respectively.

Study on Phases and Thermoelectric Properties of Bulk FexCo4-xSb12 Sintered by MM-SPS

2011 ◽  
Vol 179-180 ◽  
pp. 294-297
Author(s):  
Ke Gao Liu ◽  
Shi Lei
Keyword(s):  
Thermoelectric Properties ◽  
Thermal Constant ◽  
X Ray Diffraction ◽  
Semiconducting Materials ◽  
X Ray ◽  
Seebeck Coefficients ◽  
Plasma Sintering ◽  
Electrical Resistivities ◽  
Spark Plasma ◽  
P Type

Bulk FexCo4-xSb12 with x varies from 0.1 to 2.0 were prepared by mechanical milling (MM) and spark plasma sintering (SPS). The phases of the products were characterized by X-ray diffraction (XRD) and their thermoelectric properties were tested by electric constant instrument and laser thermal constant instrument. Experimental results show that, the major phases of bulk FexCo4-xSb12 are skutterudite. The electrical resistivities of the products increase first and then decrease. The Seebeck coefficients ( ) are negative when x=0.1 at 100 °C and 200 °C while positive at 300~500 °C. The products with x=0.5~2.0 at 100~500 °C are P type semiconducting materials due to their positive values. The thermal conductivities of most samples increase first and then decrease with x increasing and the maximum is up to 0.39 Wm-1K-1 when x=1.0. The ZT values at 200~500 °C increase first and then decrease with x increasing when x=0.1~1.0 and x=1.0~2.0 respectively and the maximum ZT value is 0.196 when x=1.5 at 400 °C.

scholarly journals Microstructure and Electrical Property of Ex-Situ and In-Situ Copper Titanium Carbide Nanocomposites

Metals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 735
Author(s):  
Nguyen Hoang Viet ◽  
Nguyen Thi Hoang Oanh
Keyword(s):  
Electrical Conductivity ◽  
Electron Microscope ◽  
Applied Pressure ◽  
Ex Situ ◽  
X Ray Diffraction ◽  
Composite Powders ◽  
Plasma Sintering ◽  
Transmission Electron ◽  
Spark Plasma

In this study, ex-situ Cu-TiC nanocomposites of 1, 3 and 5 vol. % TiC and in-situ Cu-TiH2-C nanocomposites (corresponding to 5 vol. % TiC) were prepared using ball milling and spark plasma sintering methods. Powder mixtures were milled for 4 h at 400 rpm. As-milled Cu-TiC composite powders were consolidated under an applied pressure of 70 MPa. The phase composition, and microstructure of the composite samples were characterized by X-ray diffraction, and scanning electron microscope and transmission electron microscope techniques, respectively. With the increasing TiC content from 1 to 5 vol. %, the hardness of the ex-situ composites when sintered at 600 °C changed between 161.4 and 178.5 HV and the electrical conductivity decreased from 52.1 to 47.6% IACS. In-situ Cu-TiH2-C nanocomposite sintered at 950 °C had higher hardness and electrical conductivity than ex-situ Cu-TiC composite due to having a homogenous distribution of nano reinforcement particles and dense structure.

Preparation and Characterizations of a-Fe2O3 Nanorods and their Properties

2016 ◽  
Vol 852 ◽  
pp. 346-348
Author(s):  
Hong Cai ◽  
Qing Bo Du ◽  
Ji Gui Xu ◽  
Hong Wei Shi ◽  
Jun Zhu
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Hydrothermal Method ◽  
Magnetic Measurement ◽  
Remnant Magnetization ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Fundamental Research ◽  
Scanning Electron

a-Fe2O3 nanorods over large areas were successfully synthesized by hydrothermal method, using FeCl3 as iron source and PVP as surfactant. The as-synthesized a-Fe2O3 nanorods were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and magnetic measurement system (SQUID-VSM) . The results show that the nanorods prepared by hydrothermal method with the diameter of about 70 nm and the length of about 300 nm. The magnetic properties of the synthesized nanorods were studied, and the remnant magnetization and coercivity of the α-Fe2O3 nanorods at 300K are found to be 0.07emu/g and 2300Oe, respectively. The a-Fe2O3 nanorods reported here may have opportunities for both fundamental research and technological applications.

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