Significant Influences of Selenium on the Electrical Properties of Bi2Te3 Compounds Synthesized Using Solid-State Microwave Irradiation

2012 ◽  
Vol 501 ◽  
pp. 126-128 ◽  
Author(s):  
Arej Kadhim ◽  
Arshad Hmood ◽  
Abu Hassan Haslan
Keyword(s):  
Solid State ◽  
Electrical Properties ◽  
Microwave Irradiation ◽  
Seebeck Coefficient ◽  
Thermoelectric Materials ◽  
Microwave Synthesis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Temperature Range ◽  
P Type

The thermoelectric materials based on p-type Bi2Se3xTe3 (1-x) bulk products and dispersed with x compositions of Se (x=0.0, 0.2, 0.4, 0.6, 0.8, 1.0) were fabricated using standard solid-state microwave synthesis procedures. The products were characterized by X-ray diffraction (XRD). The XRD characterizations revealed that these products are pure Bi2Te3 and Bi2Se3 with uniform structures. The electrical properties of the Bi2Te3, Bi2Se3 and Bi2Se3xTe3 (1-x) samples were measured in the temperature range of 303–523 K. The highest value of the Seebeck coefficient was 176.3 μV/ K for the Bi2Se0.6Te2.4 sample, but only 149.5 and 87.4 μV/K for the Bi2Te3 and Bi2Se3 samples, respectively.

SEEBECK COEFFICIENTS OF Mn-Si MATERIALS PREPARED BY SPARK PLASMA SINTERING

2004 ◽  
Vol 18 (16) ◽  
pp. 2279-2286 ◽  
Author(s):  
ZHI MIN WANG ◽  
YI DONG WU ◽  
YUAN JIN HE
Keyword(s):  
Seebeck Coefficient ◽  
Spark Plasma Sintering ◽  
X Ray Diffraction ◽  
X Ray ◽  
Temperature Range ◽  
Seebeck Coefficients ◽  
Plasma Sintering ◽  
Pure Phase ◽  
Spark Plasma ◽  
P Type

MnSi 1.73 and MnSi samples were grown by spark plasma sintering (SPS) from different Si / Mn ratio powders, at different sintering temperatures, and for different sintering times. X-ray diffraction (XRD) measurements showed samples containing MnSi and MnSi 1.73 and Si phases, depending on the initial stoichiometries. Measurements of the Seebeck coefficient revealed p-type conductance for all samples. The Seebeck coefficients of the samples with MnSi pure phase were very low (about 10 μ V/K) and changed little at the temperature range measured. The Seebeck coefficients of the samples with MnSi 1.73, MnSi and Si phases were similar to that of the sample with near-pure MnSi 1.73 phase, which were larger than those of the samples with MnSi 1.73 and MnSi phases, but a little smaller than those of the samples with MnSi 1.73 and Si phases. It seems that, for the samples with the same phases, larger ratio of the strongest intensity peak of MnSi 1.73 to [Formula: see text], MnSi 1.73 to [Formula: see text] or both lead to larger Seebeck coeffiecients.

Fabrication and study the effect of the laser on the properties of the compound Tl2-xHgxBa2-ySryCa2Cu3O10+δ superconductor

2018 ◽  
pp. 168
Author(s):  
A. Kareem Dahash Ali ◽  
Nihad Ali Shafeek
Keyword(s):  
Transition Temperature ◽  
Solid State ◽  
Hydrostatic Pressure ◽  
Electrical Properties ◽  
Co2 Laser ◽  
Temperature Shift ◽  
Unit Cell ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structural And Electrical Properties

This study included the fabrication of    compound (Tl2-xHgxBa2-ySryCa2Cu3O10+δ) in a manner solid state and under hydrostatic pressure ( 8 ton/cm2) and temperature annealing(850°C), and determine the effect of the laser on the structural and electrical properties elements in the compound, and various concentrations of x where (x= 0.1,0.2,0.3 ). Observed by testing the XRD The best ratio of compensation for x is 0.2 as the value of a = b = 5.3899 (A °), c = 36.21 (A °) show that the installation of four-wheel-based type and that the best temperature shift is TC= 142 K  .When you shine a CO2 laser on the models in order to recognize the effect of the laser on these models showed the study of X-ray diffraction of these samples when preparing models with different concentrations of the values ​​of x, the best ratio of compensation is 0.2 which showed an increase in the values ​​of the dimensions of the unit cell a=b = 5.3929 (A °), c = 36.238 (A°). And the best transition temperature after shedding laser is TC=144 K. 

Thermoelectric Performance of Glass Microsphere Dispersed Bi-Sb Composites at Low Temperature

2013 ◽  
Vol 743-744 ◽  
pp. 120-125
Author(s):  
Zhen Chen ◽  
Ye Mao Han ◽  
Min Zhou ◽  
Rong Jin Huang ◽  
Yuan Zhou ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Seebeck Coefficient ◽  
Thermoelectric Materials ◽  
Sem Analysis ◽  
Glass Microsphere ◽  
Thermoelectric Performance ◽  
X Ray Diffraction ◽  
X Ray ◽  
Measurement Results

In the present study, the glass microsphere dispersed Bi-Sb thermoelectric materials have been fabricated through mechanical alloying followed by pressureless sintering. The phase composition and the microstructure were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM) analysis. Electrical conductivity, Seebeck coefficient and thermal conductivity were measured in the temperature range of 77~300 K. The ZT values were calculated according to the measurement results. The results showed that the electrical conductivity, Seebeck coefficient and thermal conductivity decreased by adding glass microsphere into Bi-Sb thermoelectric materials. However, the optimum ZT value of 0.24 was obtained at 260 K, which was increased 10% than that of the Bi-Sb matrix. So it is confirmed that the thermoelectric performance of Bi-Sb-based materials can be improved by adding moderate glass microspheres.

Synthesis and Thermoelectric Properties of Ba8Ga16+xSbxGe30-2x (x=0,1) Clathrate Single Crystals

2008 ◽  
Vol 368-372 ◽  
pp. 553-555
Author(s):  
H.F. Wang ◽  
Ke Feng Cai ◽  
H. Li ◽  
L. Wang ◽  
X.L. Li
Keyword(s):  
Electron Microscopy ◽  
Seebeck Coefficient ◽  
Single Crystals ◽  
Czochralski Method ◽  
X Ray Diffraction ◽  
Flux Method ◽  
X Ray ◽  
Type Semiconductor ◽  
P Type ◽  
Scanning Electron

Ba8Ga16Ge30 clathrate material has being intensely investigated as a candidate of promising thermoelectric materials. In this work, Ba8Ga16+xSbxGe30-2x (x=0,1) single crystals have been synthesized by the Ga flux method, using high purity elemental Ba, Sb, Ga, and Ge as starting materials. Powder X-ray diffraction, Scanning electron microscopy equipped with energy-dispersive X-ray spectroscopy and Raman spectroscopy were used to characterize the single crystals. Seebeck coefficient of the crystals was measured from 300 to 800 K. The result indicates that the crystals are p-type semiconductor, which is different from the crystals synthesized by the Czochralski method. The Seebeck coefficient almost does not change after doping Sb in the whole temperature measured and it is in the range of 200 to 300μV/K.

Configurations and conformations of glycosyl sulfoxides

2010 ◽  
Vol 88 (11) ◽  
pp. 1154-1174 ◽  
Author(s):  
Hong Liang ◽  
Micheline MacKay ◽  
T. Bruce Grindley ◽  
Katherine N. Robertson ◽  
T. Stanley Cameron
Keyword(s):  
Solid State ◽  
Dft Calculations ◽  
Gas Phase ◽  
Density Functional ◽  
Lone Pair ◽  
Azido Group ◽  
X Ray Diffraction ◽  
X Ray ◽  
Comparison Of The Results ◽  
P Type

X-ray crystallographic studies of two axial glycosyl sulfoxides having RS configurations (derivatives of phenyl 2-azido-2-deoxy-1-thio-α-d-galactopyranoside S-oxide) show that they adopt anti conformations in the solid state, in contrast to previous observations and assumptions. Density functional theory (DFT) calculations at the B3lYP6–311G+(d,p)/6–31G(d) level confirm that anti conformations of both phenyl and methyl RS glycosyl sulfoxides of 2-azido-2-deoxy-α-d-pyranosides are more stable than exo-anomeric conformations in the gas phase. 1D NOE measurements indicate that the more polar exo-anomeric conformers are only populated to a slight extent in solution. The anti conformations are distorted so that the glycosyl substituents are closer to being eclipsed with H1. This distortion allows S n → σ* overlap if the sulfur lone pair is a p-type lone pair. Evidence for this overlap comes from short C1–S bond distances, as short as the comparable bond distances in the X-ray crystal structure and in the results from DFT calculations for the SS glycoside, which does adopt the expected exo-anomeric conformation, both in the solid state and in solution, and has normal n → σ* overlap. For 2-deoxy derivatives not bearing a 2-azido group, gas-phase DFT calculations at the same level indicate that the anti- and exo-anomeric conformers have comparable stabilities. Comparison of the results of the two series shows that electronegative substituents in equatorial orientations at C2 destabilize conformations with parallel S–O arrangements, the conformation favored by having an endocyclic C–O dipole antiparallel to the S–O dipole, by about 2.5 kcal mol–1 (1 cal = 4.184 J). An equatorial glycosyl sulfoxide, (SS) phenyl 3,4,6-tri-O-acetyl-2-deoxy-2-phthalimido-1-thio-β-d-glucopyranoside S-oxide, also adopts an anti conformation in the solid state as shown by X-ray diffraction. It also adopts this conformation in solution, in contrast to studies of other equatorial glycosyl sulfoxides.

Electrical Properties of Modified BNT Based Lead-Free Ceramics

2016 ◽  
Vol 872 ◽  
pp. 87-91
Author(s):  
Supalak Manotham ◽  
Tawee Tunkasiri ◽  
Pharatree Jaita ◽  
Pichitchai Butnoi ◽  
Denis Russell Sweatman ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Solid State ◽  
Electrical Properties ◽  
Sintering Temperature ◽  
Ferroelectric Properties ◽  
Lead Free ◽  
Second Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Lead Free Ceramics

The properties of modified Bi0.5Na0.5TiO3 (BNT) based lead-free ceramics were investigated. The BNT-based ceramics were prepared by a solid-state mixed oxide method Phase formation was determined by X-ray diffraction technique (XRD). The X-ray diffraction analysis of the ceramics suggested that all samples exhibited a perovskite structure without second phase. The value of dielectric constant increased with increasing in sintering temperature. Moreover, high sintering temperatures could improve ferroelectric properties of BNT base lead-free ceramics.

ELECTRICAL CONDUCTING AND THERMOELECTRIC PROPERTIES OF Ba4Na2Nb10O30−Ba3NaLaNb10O30 SYSTEM

1990 ◽  
Vol 04 (10) ◽  
pp. 681-688
Author(s):  
MASAYUKI TSUKIOKA ◽  
YASUO TANOKURA ◽  
MASAZI SHIMAZU ◽  
SHINICHIRO KUROIWA ◽  
SADAO TSUTSUMI
Keyword(s):  
Electrical Resistivity ◽  
Seebeck Coefficient ◽  
Thermoelectric Properties ◽  
Solid Solutions ◽  
Diffraction Measurement ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ceramic Samples ◽  
Electrical Conducting ◽  
P Type

Ceramic samples of BNN-BNLN ( Ba 4 Na 2 Nb 10 O 30− Ba 3 NaLaNb 10 O 30) system were prepared in flowing N 2 gas at about 1410°C, which has been confirmed to have continuous solid solutions over the whole range of BNN-BNLN system by X-ray diffraction measurement. Electrical resistivity and Seebeck coefficient measurements were carried out at temperatures from 77 K to 773 K and from 60 K to 200 K, respectively for the samples of different composition belonging to the BNN-BNLN system. These experiments revealed that all these materials were extrinsic semiconductors and change from p-type semiconductors to n-type during the process of rising temperature.

scholarly journals Study of dielectric behavior and electrical properties of hematite α-Fe2O3 doped with Zn

2012 ◽  
Vol 44 (3) ◽  
pp. 307-321 ◽  
Author(s):  
M.V. Nikolic ◽  
M.P. Slankamenac ◽  
N. Nikolic ◽  
D.L. Sekulic ◽  
O.S. Aleksic ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Spinel Phase ◽  
Dielectric Behavior ◽  
X Ray Diffraction ◽  
X Ray ◽  
Temperature Range ◽  
Zn Content ◽  
Electron Microscopy Analysis ◽  
Microscopy Analysis ◽  
Two Phases

The effects of Zn-doping on the dielectric behavior and electrical properties of bulk ?-Fe2O3 have been studied. X-ray diffraction analysis revealed the presence of two phases in all samples: hematite and spinel ZnFe2O4, with the amount of spinel phase increasing with increasing Zn content. Scanning electron microscopy analysis combined with energy dispersive X-ray spectroscopy showed that the Zn-bearing phase occurred in the form of individual spinel ZnFe2O4 grains in a hematite matrix. DC conductivity was measured in the temperature range 25-225oC (298-498 K). Impedance spectroscopy measurements in the same temperature range were carried out in the frequency range 100Hz to 10 MHz. Increase in the Zn content resulted in increased electrical conductivity and higher values of the dielectric constant. The resistance and capacitance of grains and grain boundaries were analyzed by modeling the experimental results using an equivalent circuit.

Synthesis and Characterization of Delafossite CuLaO2 for Thermoelectric Application

2007 ◽  
Vol 534-536 ◽  
pp. 1081-1084 ◽  
Author(s):  
Yuhsuke Takahashi ◽  
Hiroaki Matsushita ◽  
Akinori Katsui
Keyword(s):  
Seebeck Coefficient ◽  
Single Phase ◽  
Metallic Copper ◽  
Solid State Reaction Method ◽  
X Ray Diffraction ◽  
Mixed Powder ◽  
X Ray ◽  
Type Semiconductor ◽  
P Type

The preparation of single-phase CuLaO2 with delafossite-type structure by means of the solid-state reaction method was investigated using X-ray diffraction. The results showed that notwhistanding the fact that there was a trace of metallic copper, nearly single-phase CuLaO2 was obtained by using La(OH)3 as a lanthanum source and by firing the mixed powder with nonstoichiometric composition ratio of La(OH)3:Cu2O =1:1.425 in a vacuum at 1273 K for 10 h. The measurement of electrical conductivity and Seebeck coefficient showed that CuLaO2 thus obtained was a p-type semiconductor and had a Seebeck coefficient of approximately 70 /V/K.

scholarly journals Influence of thickness on the structure and electrical, optical properties of N-doped SnO2 film

2020 ◽  
Vol 2 (4) ◽  
pp. 240-245
Author(s):  
Nguyen Thanh Tung ◽  
Phuc Huu Dang ◽  
Tran Le
Keyword(s):  
Refractive Index ◽  
Electrical Properties ◽  
Optical Sensors ◽  
Extinction Coefficient ◽  
Optical Constants ◽  
Hole Mobility ◽  
X Ray Diffraction ◽  
Mixed Gas ◽  
X Ray ◽  
P Type

N-doped SnO2 films with varying thickness (320, 420, 520, 620, and 720 nm) were deposited at 300oC in mixed – gas sputtering Ar/N (1:1) using DC magnetron sputtering. Influence of thickness on structure, optical constants (refractive index or extinction coefficient), and electrical properties were investigated by methods such as X-ray diffraction, Uv-Vis spectra, and Hall measurement. The results show that crystalline quality and optical constants improve with increasing thickness. Specifically, NTO – 620 film has the best crystal structure and maximum values ​​such as crystal size, refractive index, and carrier mobility, as well as the lowest extinction coefficient. Also, NTO films have a cubic structure with (111) peak as the preferred peak. Besides, the hole mobility increases with the increase of the thickness and reaches the maximum value of 14.95 cm2V-1s-1 for NTO – 620 films. The electrical properties of p-type NTO films were verified by X-ray electron spectroscopy (XPS) and I-V characteristic of p – NTO/n – Si heterojunction under illumination. P-type NTO – 620 films were fabricated on n-type Si substrate had a light-to-dark current ratio of 58 at - 6V, these results showed that p-type NTO films might have a promising future in optical sensors applications.

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