The Effect of Cooling Process on the Microstructure and Electrical Transport Properties of AgSbTe2 Compound

2013 ◽  
Vol 743-744 ◽  
pp. 59-64
Author(s):  
Liang Wei Fu ◽  
Jun You Yang ◽  
Ye Xiao ◽  
Jiang Ying Peng ◽  
Ming Yang Zhang
Keyword(s):  
Electrical Resistivity ◽  
Transport Properties ◽  
Liquid Nitrogen ◽  
Electrical Transport ◽  
Cooling Water ◽  
Air Cooling ◽  
X Ray Diffraction ◽  
Cooling Process ◽  
Electrical Transport Properties ◽  
Apparent Influence

AgSbTe2compounds have been synthesized via melting and subsequent cooling processes. The effect of cooling process, from air-cooling, water quenching to liquid nitrogen-quenching, on the microstructure and the electrical transport properties of AgSbTe2has been investigated by means of powder X-ray diffraction, electron microscope, electrical resistivity, and Hall coefficient measurements. It has been found that the cooling process has apparent influence on the microstructure and corresponding electrical properties. The phase components and morphology changed as the cooling process altered. The electrical resistivity and the Seebeck coefficient of the as-prepared samples increased from air-cooled to liquid nitrogen-quenched sample.

Correlation of Microstructures with Electrical Transport Properties in Mn Doped Co Nanoferrite Particles

2012 ◽  
Vol 510-511 ◽  
pp. 487-492
Author(s):  
M. Akram ◽  
M. Anis-ur-Rehman ◽  
S. Nasir ◽  
G. Asghar
Keyword(s):  
Electrical Resistivity ◽  
Transport Properties ◽  
Cation Distribution ◽  
Electrical Transport ◽  
Research Work ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
Electrical Transport Properties ◽  
Dc Electrical Resistivity ◽  
X Ray

Magnetic nanocomposites are offering a variety of novel features and tune able properties, mainly depending on particle size, cation distribution, morphology and porosity of the prepared materials. The aim of this research work is to understand the effects of Mn doping on the microstructures and hence consequences on the electrical transport properties with shift of cation distribution in CoFe2O4. Co1-xMnxFe2O4nanocrystallite particles with stoichiometric proportion (x) varying from 0.0 to 1.0 were prepared by co-precipitation method. X-ray diffraction patterns confirmed the FCC spinel structure of synthesized particles. The crystal structure is found to be inverse cubic spinel with a space group Fd3m and the lattice constants ranges from 8.36 Å to 8.46 Å The crystallite sizes were calculated from the most intense peak (311) using the Debye-Scherrer formula for all the samples those were synthesized at reaction temperature of 70°C. Then samples were sintered at 600°C for 3 hours, characterized by X-ray diffraction at room temperature and DC electrical resistivity measurements were done as a function of temperature by two-probe method from 370 K to 690 K. The measurements showed that DC electrical resistivity decreased with increase in temperature ensuring the semiconductor nature of the material in this temperature range. DC electrical resistivity results were discussed in terms of polaron hopping model under the effects of cation distribution. AC electrical properties were also analyzed. All the observed properties were correlated with observed microstructures.

Study of Structural and Electrical Transport Properties of Polycrystalline La1-XCaXMnO3 (x=0.33, 0.5 and 0.9) Prepared by a Co-Precipitation Method

2013 ◽  
Vol 652-654 ◽  
pp. 576-580 ◽  
Author(s):  
Mya Theingi ◽  
Ji Ma ◽  
Hui Zhang ◽  
Xiang Gao ◽  
Jian Hong Yi ◽  
...  
Keyword(s):  
Transport Properties ◽  
Electrical Transport ◽  
Perovskite Phase ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
Electrical Transport Properties ◽  
X Ray ◽  
Manganite Perovskite ◽  
Polycrystalline Ceramics ◽  
Co Precipitation

Manganite perovskite La1-xCaxMnO3(x=0.33, 0.5 and 0.9) have been prepared by chemical co-precipitation method. Ammonium carbonate was used to coprecipitate lanthanum, calcium and manganese ions as carbonates under basic condition. This precursor on calcining at 900°C yields La-Ca-Mn-O perovskite phase. Follow by sintering at 1200°C after the powders were pressed into pellets gave La1-xCaxMnO3(LCMO) polycrystalline ceramics. The crystal phases of the resulting powders and ceramics were examined by X-ray diffraction (XRD) technique. The morphology of the powders was observed by scanning electron microscopy (SEM) and electrical transport properties of ceramics were measured by conventional four-point probe technique.

scholarly journals Electrical Transport Properties of R3Ag4Sn4 (R = Gd, Tb, Dy, Ho) Compounds

2018 ◽  
Vol 19 (4) ◽  
pp. 316-321
Author(s):  
I. Romaniv ◽  
B. Kuzhel ◽  
L. Romaka ◽  
V. Pavlyuk
Keyword(s):  
Electrical Resistivity ◽  
Transport Properties ◽  
Temperature Interval ◽  
Electrical Transport ◽  
Magnetic Ordering ◽  
Structure Type ◽  
Electrical Transport Properties ◽  
Interval Relation ◽  
Slope Change ◽  
Magnetic And Electric Properties

Electrical transport properties of the R3Ag4Sn4 (R = Gd, Tb, Dy, Ho) intermetallics crystallized in the orthorhombic Gd3Cu4Ge4 structure type (space group Immm) were studied in the temperature interval 11 – 300 K. Measurements of the temperature dependencies of electrical resistivity (r(T)) showed that all the studied compounds are characterized by metallic type of conductivity. The slope change of the resistivity at low temperature part of r(T) dependencies for Gd3Ag4Sn4, Tb3Ag4Sn4 and Dy3Ag4Sn4 compounds is connected with their magnetic ordering. Change of the resistivity caused by magnetic ordering was not observed for the Ho3Ag4Sn4 compound in the studied temperature interval. Relation between magnetic and electric properties of the investigated R3Ag4Sn4 compounds was analyzed.

scholarly journals The Undoped Polycrystalline Diamond Film—Electrical Transport Properties

Sensors ◽  
2021 ◽  
Vol 21 (18) ◽  
pp. 6113
Author(s):  
Szymon Łoś ◽  
Kazimierz Fabisiak ◽  
Kazimierz Paprocki ◽  
Mirosław Szybowicz ◽  
Anna Dychalska
Keyword(s):  
Transport Properties ◽  
Electrical Transport ◽  
Diamond Films ◽  
Polycrystalline Diamond ◽  
Localized States ◽  
X Ray Diffraction ◽  
Electrical Transport Properties ◽  
Temperature Range ◽  
Hot Filament ◽  
Si Wafer

The polycrystalline diamonds were synthesized on n-type single crystalline Si wafer by Hot Filament CVD method. The structural properties of the obtained diamond films were checked by X-ray diffraction and Raman spectroscopy. The conductivity of n-Si/p-diamond, sandwiched between two electrodes, was measured in the temperature range of 90–300 K in a closed cycle cryostat under vacuum. In the temperature range of (200–300 K), the experimental data of the conductivity were used to obtain the activation energies Ea which comes out to be in the range of 60–228 meV. In the low temperature region i.e., below 200 K, the conductivity increases very slowly with temperature, which indicates that the conduction occurs via Mott variable range hopping in the localized states near Fermi level. The densities of localized states in diamond films were calculated using Mott’s model and were found to be in the range of 9×1013 to 5×1014eV−1cm−3 depending on the diamond’s surface hydrogenation level. The Mott’s model allowed estimating primal parameters like average hopping range and hopping energy. It has been shown that the surface hydrogenation may play a crucial role in tuning transport properties.

Structural, Magnetic, and Transport Properties of La0.62Sb0.38MnO3 Ceramic

2013 ◽  
Vol 800 ◽  
pp. 398-401 ◽  
Author(s):  
Qiang Wang ◽  
Ping Duan ◽  
Ji You Wang ◽  
Lei Chang ◽  
Jin Liang Zhao ◽  
...  
Keyword(s):  
Transport Properties ◽  
Electrical Transport ◽  
State Transition ◽  
Ferromagnetic State ◽  
Solid State Reaction Method ◽  
X Ray Diffraction ◽  
Hexagonal Crystal ◽  
Electrical Transport Properties ◽  
Metal Insulator ◽  
X Ray

The polycrystalline La0.62Sb0.38MnO3 sample has been prepared by the solid-state reaction method. Structural, magnetic and electrical transport properties have been researched. X-ray diffraction analysis confirms the hexagonal crystal symmetry. Magnetization measurements indicate La0.62Sb0.38MnO3 experienced from paramagnetic to ferromagnetic state transition with decreasing temperature at about 225 K. Resistivity dependences on temperature exhibit metal-insulator transition (MIT), and the maximum magnetoresistance (MR) ratio is about 33 % at temperature of 189 K and magnetic field of 2 T.

ELECTRICAL TRANSPORT PROPERTIES OF SOME METALLIC GLASSES

1993 ◽  
Vol 07 (20) ◽  
pp. 1295-1299 ◽  
Author(s):  
P. VENUGOPAL REDDY ◽  
S. SHEKHAR ◽  
Y. PURUSHOTHAM
Keyword(s):  
Electrical Resistivity ◽  
Transport Properties ◽  
Thermoelectric Power ◽  
Temperature Variation ◽  
Metallic Glasses ◽  
Electrical Transport ◽  
Electrical Transport Properties ◽  
Temperature Range ◽  
Increasing Temperature

Electrical resistivity and thermoelectric power of glassy ribbons having compositions Fe 81 B 13.5 Si 3.5 C 2, Fe 67 Co 18 B 14 Si 1, Fe 39 Ni 39 Mo 4 Si 6 B 12, and Co 53 Ni 25 Fe 5 Si 11 B 6 have been studied over a temperature range of 300–750 K. The electrical transport properties of these materials are found to increase with increasing temperature, and their temperature variation has been explained on the basis of Ziman's theory.

Structural and Electrical Transport Properties of La0.67Ba0.33Mn1-yTiyO3 Ceramics

2012 ◽  
Vol 501 ◽  
pp. 86-90
Author(s):  
Zainuddin Zalita ◽  
Shaari Abdul Halim
Keyword(s):  
Transport Properties ◽  
Electrical Transport ◽  
Single Phase ◽  
Small Polaron ◽  
Lattice Parameter ◽  
X Ray Diffraction ◽  
Electrical Transport Properties ◽  
Polaron Hopping ◽  
Phase Compound ◽  
Ti Content

The structural and electrical transport properties of La0.67Ba0.33Mn1-yTiyO3 manganite, with y = 0.00, 0.05, 0.10, 0.15, 0.20, 0.40 and 0.60, prepared using the solid state reaction technique have been investigated. The X-ray diffraction spectra of the Ti substituted samples showed the formation of single phase compound with Pm3m cubic structure except for the y = 0.60 sample, which showed La2Ti2O7 phase formation. Lattice parameter increased with Ti content and then decreased at y = 0.60. Resistivity versus temperature study showed that only samples with y = 0.05 and 0.10 exhibited both metallic and semiconductor-like behaviour with the metal-insulator transition temperature, Tp of 167 K and 43 K, respectively. At higher Ti concentration the samples only showed the semiconducting behaviour. At T < Tp the resistivity curves followed the ρ = ρo1 + ρ1T2 relation and for T > Tp, the curves can be fitted with the nearest neighbour hopping (NNH), variable range hopping (VRH) or/and the small polaron hopping (SPH) models.

Investigation of electrical transport properties of Bi0.5Sb1.5Te2.7Se0.3 alloys prepared by high-pressure method

2015 ◽  
Vol 08 (05) ◽  
pp. 1550055 ◽  
Author(s):  
Xin Guo ◽  
Xiaopeng Jia ◽  
Yuewen Zhang ◽  
Hairui Sun ◽  
Bing Sun ◽  
...  
Keyword(s):  
High Pressure ◽  
Electrical Resistivity ◽  
Seebeck Coefficient ◽  
Transport Properties ◽  
Electrical Transport ◽  
Room Temperature ◽  
Synthesis Process ◽  
Electrical Transport Properties ◽  
Pressure Method ◽  
Measurement Results

The quaternary Bi 0.5 Sb 1.5 Te 2.7 Se 0.3 alloys have been successfully synthesized within 25 min by high-pressure method. The pressure-dependent electrical transport properties of the as-prepared Bi 0.5 Sb 1.5 Te 2.7 Se 0.3 alloys are carefully investigated at room temperature. The measurement results indicate that the electrical resistivity and the Seebeck coefficient reveal a strong correlation with the increase of synthesis pressure. The carrier concentration and mobility are modulated effectively due to the effects of synthesis pressure and composition, leading to an improvement in the power factor of Bi 0.5 Sb 1.5 Te 2.7 Se 0.3. These results suggest that the utilization of pressure during the synthesis process provides an effective and controllable strategy to optimize the electrical transport properties of the ( Bi , Sb )2( Te , Se )3 alloys.

Thermoelectric Properties of Single-Wall Carbon Nanotubes

1998 ◽  
Vol 545 ◽  
Author(s):  
L. Grigorian ◽  
G. Sumanasekera ◽  
P. C Eklund
Keyword(s):  
Transport Properties ◽  
Electrical Transport ◽  
Magnetic Moments ◽  
Scattering Data ◽  
Single Wall Carbon Nanotubes ◽  
X Ray Diffraction ◽  
Electrical Transport Properties ◽  
Single Wall Carbon ◽  
Impurity Atoms ◽  
Kondo System

AbstractResults of the temperature dependence of the thermoelectric power and fourprobe resistance of single wall carbon nanotube mats are presented. The data are interpreted in terms of the response of a percolating network of metallic nanotube bundles. To the best of our knowledge, the work represents the first systematic study of the transport properties of a series of samples prepared using different transition metal-Y growth catalysts. Although x-ray diffraction and Raman scattering data indicate these samples are nominally the same, we find that the identity of the catalyst has a pronounced effect on the electrical transport properties. The data are interpreted qualitatively in terms of a dilute Kondo system involving the coupling of the the localized magnetic moments of impurity atoms (derived from the catalyst), and the conduction electron spins in the nanotube walls.

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