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.

Electrical transport properties of single-crystalline Mn–Zn ferrous ferrite

2001 ◽  
Vol 16 (3) ◽  
pp. 774-777 ◽  
Author(s):  
Yong-Chae Chung ◽  
Han-Ill Yoo
Keyword(s):  
Transport Properties ◽  
Thermoelectric Power ◽  
Electrical Transport ◽  
Small Polaron ◽  
Electrical Transport Properties ◽  
Polaron Hopping ◽  
Single Crystalline ◽  
Small Polaron Hopping ◽  
Hopping Model ◽  
Cation Redistribution

Electrical transport properties, electrical conductivity, and thermoelectric power of a single-crystalline Mn0.45Zn0.43Fe2.12O4 were measured as functions of temperature in the range of 25 to 1000 °C. According to the small polaron hopping model, the values of the activation energy for small polaron hopping (EH) were obtained from the conductivity data in three different temperature regions: 0.032 eV for T < TC, 0.12 eV for TC < T < 600 °C, and 0.25 eV for 600 °C < T < 1000 °C. The behavior of conductivity and thermoelectric power data above TC is discussed in connection with cation redistribution.

Electrical Transport Properties of Polycrystalline Chromium Vanadate

1987 ◽  
Vol 42 (6) ◽  
pp. 577-581 ◽  
Author(s):  
Shubha Gupta ◽  
Y. P. Yadava ◽  
R. A. Singh
Keyword(s):  
Transport Properties ◽  
Electrical Transport ◽  
Energy Gap ◽  
Small Polaron ◽  
Charge Carrier Mobility ◽  
Normal Band ◽  
Electrical Transport Properties ◽  
Polaron Hopping ◽  
Intrinsic Nature ◽  
Type Semiconductor

Electrical transport properties of polycrystalline chromium vanadate (CrVO4) have been studied by measuring its a. c. and d.c. electrical conductivities, thermoelectric power and dielectric constant in the temperature range 300-1000 K. CrVO4 is a p-type semiconductor with an energy gap of 3.6 eV. The compound exhibits extrinsic nature up to 750 K and after that its intrinsic nature arises. The activation energy and charge carrier mobility in the temperature ranges 300-750 K and 750- 1000 K show that the conduction in the extrinsic region is due to a small polaron hopping mechanism and in the intrinsic region it is of the normal band type.

Reinvestigation the Thermal and Electrical Transport Properties of Tl7Sb2

2013 ◽  
Vol 802 ◽  
pp. 284-288
Author(s):  
Anek Charoenphakdee ◽  
Adul Harnwangmuang ◽  
Tosawat Seetawan ◽  
Chesta Ruttanapun ◽  
Vittaya Amornkitbamrung ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Transport Properties ◽  
Electrical Transport ◽  
Room Temperature ◽  
Lattice Parameter ◽  
Electronic Contribution ◽  
Electrical Transport Properties ◽  
Space Group ◽  
Crystal System ◽  
Thallium Compounds

The authors examined the thermal and electrical transport properties of Tl7Sb2 at temperatures ranging from room temperature to 400 K. The crystal system of Tl7Sb2 is cubic with the lattice parameter a = 1.16053 nm and the space group is Im3m. The polycrystalline samples were prepared by melting stoichiometric amounts of thallium and antimony. Although, usually the thermal conductivity of thallium compounds is very low (<1 Wm-1K-1), that of Tl7Sb2 was relatively high (~13 Wm-1K-1 at room temperature). This is because of the large electronic contribution to the thermal conductivity.

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.

Structural and electrical properties of Nd1.7Ba0.3Ni0.9Cr0.1O4+δ compound

2012 ◽  
Vol 27 (3) ◽  
pp. 184-188 ◽  
Author(s):  
Manel Jammali ◽  
Rached Ben Hassen ◽  
Jan Rohlicek
Keyword(s):  
Electrical Transport ◽  
Small Polaron ◽  
Sol Gel ◽  
Polycrystalline Sample ◽  
Xrd Analysis ◽  
Electrical Transport Properties ◽  
Polaron Hopping ◽  
X Ray ◽  
Cell Parameters ◽  
Structural And Electrical Properties

The Nd1.7Ba0.3Ni0.9Cr0.1O4+δ polycrystalline sample was synthesized by the sol–gel process and a subsequent annealing at 1523 K in 1 atm of flowing argon. X-ray diffraction (XRD) analysis and electrical transport properties have been investigated as well. The oxygen non-stoichiometry was determined by iodometric titration. The sample shows adoption of the K2NiF4-type structure based on a tolerance factor calculation. Rietveld refinement of the crystal structure from X-ray powder diffraction data confirmed that Nd1.7Ba0.3Ni0.9Cr0.1O4+δ adopts the tetragonal structure (space group I4/mmm, Z = 2). The room temperature unit-cell parameters are determined to be a = 3.82515(2) and c = 12.47528(6) Å. The reliability factors are: RB = 0.043, Rwp = 0.012 and χ2 = 3.00. The Nd1.7Ba0.3Ni0.9Cr0.1O4+δ compound exhibits a semi-conductive behaviour. The electrical transport mechanism has been investigated and it agrees with the adiabatic small polaron hopping model in the temperature range 313 K ≤ T ≤ 708 K.

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 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.

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 ELECTRICAL TRANSPORT AND AC SUSCEPTIBILITY IN LaMn1-xCuxO3

2005 ◽  
Vol 19 (06) ◽  
pp. 317-330 ◽  
Author(s):  
MANORANJAN KAR ◽  
S. RAVI
Keyword(s):  
Transition Temperature ◽  
Electrical Transport ◽  
Small Polaron ◽  
Ac Susceptibility ◽  
Ferromagnetic Transition ◽  
X Ray Diffraction ◽  
Polaron Hopping ◽  
Phase Form ◽  
Resistivity Data ◽  
Diffraction Patterns

LaMn 1-x Cu x O 3 compounds have been prepared in single phase form for x = 0 to 0.30. X-ray diffraction patterns recorded at room temperature could be mostly refined using Pbnm space group. Paramagnetic-to-ferromagnetic transitions have been observed up to x = 0.30, from ac susceptibility measurements. Metal–insulator transition in the vicinity of ferromagnetic transition temperature has been observed for x = 0.05 and the resistivity data in the metallic region could be explained in terms of electron–electron and electron–magnon scattering mechanisms. Further increase in Cu-doping beyond x = 0.05 leads to systematic decrease in ferromagnetic transition temperature and ultimately ferromagnetism is destroyed for x = 0.40. The resistivity data of all samples except x = 0.05 exhibit semiconducting behaviors and they could be mostly explained using the adiabatic small polaron hopping model.

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