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 AND MAGNETO-TRANSPORT PROPERTIES OF La0.8Sr0.2MnO3

2011 ◽  
Vol 25 (28) ◽  
pp. 3825-3833
Author(s):  
S. T. SHILAN ◽  
L. S. EWE ◽  
R. ABD-SHUKOR
Keyword(s):  
Transport Properties ◽  
Sintering Temperature ◽  
Small Polaron ◽  
Variable Range Hopping ◽  
Polaron Hopping ◽  
Variable Range ◽  
Small Polaron Hopping ◽  
Paramagnetic Region ◽  
Magneto Resistance ◽  
Hopping Model

The effects of sintering temperature on the electrical and magneto-transport properties of La 0.8 Sr 0.2 MnO 3 compounds prepared by employing a chemical co-precipitation route sintered at 1120°C, 1220°C and 1320°C are reported. The X-ray powder diffraction patterns for all samples can be indexed to the rhombohedra structure with R3C space group. The insulator–metal transition temperature remained nearly constant (~291 K) for all samples. The magneto resistance (MR) values were found to decrease noticeably as the sintering temperature was increased from 1120°C to 1320°C. Above 0.3 T, the magneto resistance was influenced by To values, which indicates the bending of Mn–O–Mn bond. The resistivity data were fitted with several equations in the metallic (ferromagnetic) region. In the insulating (paramagnetic) region, the variable range hopping and small polaron hopping models were used to compute the density of states at the Fermi level, N(EF), and activation energy (Ea) of the electrons. The resistivities can be fitted well with ρ–T2 and ρ–T2.5 curves. The variable range hopping model and small polaron hopping model fitted very well at high temperature regions, indicating that small polaron hopping might be responsible for the conduction. La 0.8 Sr 0.2 MnO 3 sintered at 1220°C demonstrated the highest MR of 6.5% in 1 T magnetic field.

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.

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.

Thermal Stability and Electrical Transport Properties of Single-Crystalline β-Zn4Sb3 Co-doped by Ga/Sn

2017 ◽  
Vol 46 (12) ◽  
pp. 6804-6810 ◽  
Author(s):  
Shuping Deng ◽  
Yu Tang ◽  
Decong Li ◽  
Hongxia Liu ◽  
Zhong Chen ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Transport Properties ◽  
Electrical Transport ◽  
Electrical Transport Properties ◽  
Single Crystalline ◽  
Co Doped

Magnetic and electrical transport properties of Sr2Ti1−xCoxO4 ceramics by sol–gel

2017 ◽  
Vol 31 (17) ◽  
pp. 1750195
Author(s):  
Li Zhang ◽  
Yibao Li ◽  
Zhen Tang ◽  
Yan Deng ◽  
Hui Yuan ◽  
...  
Keyword(s):  
Transport Properties ◽  
Electrical Transport ◽  
Low Temperatures ◽  
Sol Gel ◽  
Variable Range Hopping ◽  
Electrical Transport Properties ◽  
Co Doping ◽  
Hopping Model ◽  
Variable Range Hopping Model ◽  
Co Doped

Microstructures, electrical transport and magnetic properties of Sr[Formula: see text]Ti[Formula: see text]Co[Formula: see text]O[Formula: see text] ceramics are investigated. With Co doping, the Sr[Formula: see text]Ti[Formula: see text]Co[Formula: see text]O[Formula: see text] ceramics remain tetragonal structure while the grain size is decreased with doping. Magnetic moment is enhanced with Co doping and ferromagnetism is observed at low temperatures for Co-doped Sr[Formula: see text]TiO[Formula: see text]. The Sr[Formula: see text]Ti[Formula: see text]Co[Formula: see text]O[Formula: see text] and Sr[Formula: see text]Ti[Formula: see text]Co[Formula: see text]O[Formula: see text] show semiconductor-like transport properties, which can be well fitted by Mott variable range hopping model. The results will provide an effective route to synthesize Sr[Formula: see text]Ti[Formula: see text]Co[Formula: see text]O[Formula: see text] ceramics as well as to investigate the physical properties.

Structure and Transport Properties of Sr0.75-xCaxY0.25Co0.25Mn0.75O3-δ (0 ≤ x ≤ 0.6)

2010 ◽  
Vol 1256 ◽  
Author(s):  
Alexandra Galeeva ◽  
Philipp Napolsky ◽  
Sergey Istomin ◽  
Andrey Gippius ◽  
Dmitry Khokhlov
Keyword(s):  
Transport Properties ◽  
Low Temperatures ◽  
Small Polaron ◽  
Calcium Content ◽  
Complex Oxide ◽  
Dc Conductivity ◽  
Polaron Hopping ◽  
Ceramic Samples ◽  
Distortion Parameters ◽  
Hopping Model

AbstractNew complex oxide Sr0.75-xCaxY0.25Co0.25Mn0.75O3-δ with a perovskite-like structure has been synthesized and characterized. DC and AC transport properties of ceramic samples have been studied in the temperature range 4.2K – 1173K. DC conductivity data at T > 300K are discussed in terms of the small polaron hopping model. Dependence of the polaron activation energy on the calcium content is found to correlate with the change of structural distortion parameters. Both the temperature dependence of DC conductivity and the frequency dependence of the real part of the admittance reveal hopping transport at low temperatures.

Sign in / Sign up

Export Citation Format

Share Document