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.

Flux Growth and Dielectric Properties of Relaxor-Based Pb(In1/2Nb1/2)O3-PbTiO3 Single Crystals

2005 ◽  
Vol 475-479 ◽  
pp. 4179-4182 ◽  
Author(s):  
Hui Qing Fan
Keyword(s):  
Electron Microscopy ◽  
Dielectric Properties ◽  
Single Crystals ◽  
Lead Titanate ◽  
X Ray Diffraction ◽  
Flux Method ◽  
X Ray ◽  
Phase Development ◽  
Transmission Electron ◽  
Scanning Electron

Relaxor-based piezoelectric single crystals of lead indium niobate-lead titanate (0.63Pb(In1/2Nb1/2)-0.37PbTiO3, abbreviated as PIN-PT), in the vicinity of the morphotropic phase boundary, were prepared by a flux method. The compositions of the flux, Pb3O4 or PbF2, play different role in perovskite stability and phase development. Thus, pure perovskite PIN-PT single crystals with the size of 2~5 mm were obtained by using Pb3O4 flux as well as a small amount of B2O3 additive. The microstructure and the phase development of the as-grown single crystals were investigated by scanning electron microscopy and transmission electron microscopy and X-ray diffraction. Furthermore, the dielectric properties of the <100>-oriented PIN-PT single crystals were measured in the temperature range between 20°C and 400°C.

N-type Ba0.2Co4Sb11.5Te0.5: Optimization of thermoelectric properties by different pressures

2019 ◽  
Vol 33 (03) ◽  
pp. 1950027 ◽  
Author(s):  
Jiaxiang Chen ◽  
Xiaopeng Jia ◽  
Yuewen Zhang ◽  
Haiqiang Liu ◽  
Baomin Liu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Seebeck Coefficient ◽  
Room Temperature ◽  
X Ray Diffraction ◽  
Absolute Value ◽  
X Ray ◽  
Coefficient Increase ◽  
Maximum Power Factor ◽  
Scanning Electron

The polycrystalline skutterudite [Formula: see text] were successfully synthesized from 1.5 GPa to 3.5 GPa by the high pressure and high temperature (HPHT) method. Negative Seebeck coefficient confirmed the n-type conductivity of all samples. The phase compositions of samples were investigated by X-ray diffraction (XRD) and the microstructures were observed by scanning electron microscopy (SEM). It was found that the grains appeared smaller and the grain boundaries became more abundant when pressures were higher. We measured the electrical properties from room temperature to 723 K. Both the electrical resistivity and absolute value of Seebeck coefficient increase with the increasing synthetic pressure. At 723 K, the maximum power factor of [Formula: see text] was obtained for the sample synthesized under 3 GPa. The maximum ZT value of 0.61 was reached by [Formula: see text] synthesized under 3 GPa and measured at 723 K.

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 AgSn[Bi1−xSbx]Se3: Synthesis, Structural Characterization, and Electrical Behavior

Crystals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 864
Author(s):  
Paulina Valencia-Gálvez ◽  
Daniela Delgado ◽  
María Luisa López ◽  
Inmaculada Álvarez-Serrano ◽  
Silvana Moris ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Seebeck Coefficient ◽  
X Ray ◽  
Average Value ◽  
Transmission Electron ◽  
Semiconductor Behavior ◽  
Type Semiconductor ◽  
Diffraction Patterns ◽  
Increasing Temperature ◽  
P Type

Herein, we report the synthesis, characterization, and electrical properties of lead-free AgSnm[Bi1−xSbx]Se2+m (m = 1, 2) selenides. Powder X-ray diffraction patterns and Rietveld refinement data revealed that these selenides consisted of phases related to NaCl-type crystal structure. The microstructures and morphologies of the selenides were investigated by backscattered scanning electron microscopy, energy-dispersive X-ray spectroscopy, and high-resolution transmission electron microscopy. The studied AgSnm[Bi1−xSbx]Se2+m systems exhibited typical p-type semiconductor behavior with a carrier concentration of approximately ~+1020 cm−3. The electrical conductivity of AgSnm[Bi1−xSbx]Se2+m decreased from ~3.0 to ~10−3 S·cm−1 at room temperature (RT) with an increase in m from 1 to 2, and the Seebeck coefficient increased almost linearly with increasing temperature. Furthermore, the Seebeck coefficient of AgSn[Bi1−xSbx]Se3 increased from ~+36 to +50 μV·K−1 with increasing Sb content (x) at RT, while its average value determined for AgSn2[Bi1−xSbx]Se4 was approximately ~+4.5 μV·K−1.

Effect of Selenium on Structure and Electrical Property for Bi0.4Sb1.6Se3xTe3(1-x) Novel Hexagonal Rods

2013 ◽  
Vol 756 ◽  
pp. 80-84
Author(s):  
Arej Kadhim ◽  
Arshad Hmood ◽  
Abu Hassan Haslan
Keyword(s):  
Electron Microscopy ◽  
Electrical Conductivity ◽  
Seebeck Coefficient ◽  
Rhombohedral Phase ◽  
Orthorhombic Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Maximum Power Factor ◽  
Microscopy Images ◽  
Scanning Electron

Novel hexagonal rods of Bi0.4Sb1.6Se3xTe3(1-x) (0.0≤x≤1.0) were synthesized successfully through solid-state microwave synthesis. These hexagonal rods were explored using field emission scanning electron microscopy images. The X-ray diffraction results indicate that the powders (0.0≤x≤0.8) can be indexed as the rhombohedral phase, whereas the sample with x=1.0 has an orthorhombic phase structure. The electrical conductivity gradually decreases as Se increased, resulting in an increase in the Seebeck coefficient. Ascribing to the increased Seebeck coefficient for the sample with x=0.8, the maximum power factor is 7.47 mW/mK2 at 373 K.

scholarly journals Элементное и структурное картирование объемных кристаллов (Al-=SUB=-x-=/SUB=-Ga-=SUB=-1-x-=/SUB=-)-=SUB=-2-=/SUB=-O-=SUB=-3-=/SUB=-, полученных методом Чохральского

2021 ◽  
Vol 47 (5) ◽  
pp. 19
Author(s):  
Д.А. Бауман ◽  
Л.А. Пьянкова ◽  
А.В. Кремлева ◽  
В.А. Спиридонов ◽  
Д.Ю. Панов ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Surface Layer ◽  
Czochralski Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

Using X-ray fluorescence and X-ray diffraction mapping, as well as scanning electron microscopy, the distribution of aluminum in the surface layer of the (AlxGa1-x) 2O3 crystal obtained by the Czochralski method using a sapphire seed was studied. It is shown that the distribution of aluminum correlates with the change in the physical broadening of the diffraction maxima of the system of planes (h00) of the crystal and is associated with the distance from the seeding zone.

Diversity in crystal production by some bird's nest fungi (Nidulariaceae) in culture

1997 ◽  
Vol 75 (6) ◽  
pp. 850-856 ◽  
Author(s):  
Tracy C. Shinners ◽  
Jalpa P. Tewari
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Calcium Oxalate ◽  
Single Crystals ◽  
Morphological Variation ◽  
Energy Dispersive ◽  
X Ray Diffraction ◽  
Habitat Distribution ◽  
X Ray ◽  
Scanning Electron

Hyphae of many species of bird's nest fungi (Nidulariaceae) were examined for the presence of crystals. Scanning electron microscopy revealed crystals typical of calcium oxalate associated with hyphae. Crystal depositions included complete hyphal encrustation, organized druses, randomly arranged groups, single crystals, and relatively "clean" hyphae. The majority of crystals could be morphologically classified as styloid, raphide, or bipyramidal type. Energy-dispersive X-ray microanalyses confirmed that all crystal types were rich in calcium, and X-ray diffraction identified both the dihydrate (weddellite) and monohydrate (whewellite) forms of calcium oxalate. Morphological variation of crystals was species and medium specific, with generally more crystals being produced on relatively calcium-rich V8 juice agar than on PDA. No association was found between crystal types and geographic and habitat distribution of species. Keywords: wood rotting fungus, decomposition, calcium oxalate.

Thermoelectric Properties of BixSbyTezSew Nanocomposite Materials

2008 ◽  
Vol 55-57 ◽  
pp. 809-812 ◽  
Author(s):  
V. Kosalathip ◽  
T. Kumpeerapun ◽  
S. Migot ◽  
B. Lenoir ◽  
A. Dauscher
Keyword(s):  
Electron Microscopy ◽  
Room Temperature ◽  
Nanocomposite Materials ◽  
Nano Particle ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
P Type ◽  
Cold Pressed ◽  
Scanning Electron

Nanopowders of n-type (Bi0.95Sb0.05)2(Te0.95Se0.05)3 and p-type (Bi0.2Sb0.8)2Te3 have been synthesized by laser fracture of micron-sized powders in water. These alloys are the best conventional thermoelectric materials for use in room temperature applications. The nanopowders have been characterized by x-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The nanopowders have been mechanically mixed in different ratios with the micron sized powders. These mixtures have then been cold pressed in order to perform thermoelectric characterization and to see the influence of nano-particle inclusions on the transport properties.

Structural and Thermoelectric Properties of Bi0.4Sb1.6Se3xTe3(1-X) Quaternary Compound

2012 ◽  
Vol 620 ◽  
pp. 55-59
Author(s):  
Arej Kadhim ◽  
Arshad Hmood ◽  
Abu Hassan Haslan
Keyword(s):  
Electron Microscopy ◽  
Seebeck Coefficient ◽  
Rhombohedral Phase ◽  
Orthorhombic Phase ◽  
X Ray Diffraction ◽  
Quaternary Compound ◽  
X Ray ◽  
Maximum Power Factor ◽  
Microscopy Images ◽  
Scanning Electron

Novel hexagonal rods of Bi0.4Sb1.6Se3xTe3(1-x) (0.0x1.0) were synthesized successfully through solid-state microwave synthesis. These hexagonal rods were explored using field emission scanning electron microscopy images. The X-ray diffraction results indicate that the powders (0.0x0.8) can be indexed as the rhombohedral phase, whereas the sample with x=1.0 has an orthorhombic phase structure. The electrical conductivity gradually decreases as Se increased, resulting in an increase in the Seebeck coefficient. Ascribing to the increased Seebeck coefficient for the sample with x=0.8, the maximum power factor is 7.47 mW/mK2 at 373 K.

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