CHARACTERIZATION OF LiPb2V5O15 CERAMICS USING IMPEDANCE SPECTROSCOPY

2009 ◽  
Vol 23 (05) ◽  
pp. 755-764 ◽  
Author(s):  
P. S. DAS ◽  
P. K. CHAKRABORTY ◽  
BANARJI BEHERA ◽  
R. N. P. CHOUDHARY
Keyword(s):  
Impedance Spectroscopy ◽  
Negative Temperature Coefficient ◽  
Complex Impedance ◽  
Negative Temperature ◽  
Polycrystalline Sample ◽  
Orthorhombic Crystal System ◽  
Temperature Coefficient Of Resistance ◽  
Orthorhombic Crystal ◽  
Impedance Parameters

The polycrystalline sample of LiPb 2 V 5 O 15 was prepared by a mixed oxide method at low temperature (i.e. 550°C). Preliminary structural analysis confirmed the formation of the compound of an orthorhombic crystal system. The impedance parameters of the material were studied using complex impedance spectroscopy (CIS) in a wide temperature (i.e. 30–450°C) and frequency (i.e. 102–106 Hz) range. From the complex impedance plots, grain/grain boundary effects and relaxation phenomenon were observed above 30°C. Study of electrical conductivity suggests that the compound exhibits the negative temperature coefficient of resistance (NTCR) behavior like a semiconductor.

STRUCTURAL AND IMPEDANCE CHARACTERISTICS OF KPb2V5O15

2011 ◽  
Vol 25 (28) ◽  
pp. 3745-3753
Author(s):  
P. S. DAS ◽  
P. K. CHAKRABORTY ◽  
BANARJI BEHERA ◽  
R. N. P. CHOUDHARY
Keyword(s):  
Boundary Effect ◽  
Complex Impedance ◽  
Negative Temperature ◽  
Polycrystalline Sample ◽  
Homogeneous Distribution ◽  
Orthorhombic Crystal ◽  
Ac Electrical Conductivity ◽  
Orthorhombic Crystal Structure ◽  
Impedance Characteristics ◽  
Sem Micrograph

The polycrystalline sample of KPb 2 V 5 O 15 was prepared by a mixed-oxide method relatively at low temperature (i.e., 550°C). X-ray diffraction studies of the compound showed the formation of single phase orthorhombic crystal structure at room temperature. SEM micrograph showed the homogeneous distribution of grains throughout the sample. Electric properties were analyzed using the complex impedance spectroscopy. The modulus plot showed the presence of both the grain and grain boundary effect. The bulk impedance evaluated from the Nyquist plots was observed to decrease with the rise in temperature, showing a negative temperature coefficient of resistance. The variation of AC electrical conductivity (σ AC ) was measured in a wide temperature (30–500°C) and frequency (102–106 Hz) range. The activation energy of the compound calculated from both the impedance and modulus spectrum was found to be the same.

scholarly journals Structure, dielectric and electrical properties of relaxor lead-free double perovskite: Nd2NiMnO6

2019 ◽  
Vol 13 (1) ◽  
pp. 1-11 ◽  
Author(s):  
Rutuparna Das ◽  
Ram Choudhary
Keyword(s):  
Ac Conductivity ◽  
Negative Temperature Coefficient ◽  
Complex Impedance ◽  
Double Perovskite ◽  
Negative Temperature ◽  
Solid State Reaction Method ◽  
Temperature Coefficient Of Resistance ◽  
X Ray ◽  
Impedance Data ◽  
Nyquist Plots

In this paper, dielectric relaxor, impedance, AC conductivity and electrical modulus of double perovskite Nd2NiMnO6, prepared by a solid state reaction method and sintered at 1250?C, have been reported in the wide temperature (25-150?C) and frequency (1 kHz-1MHz) ranges. From the preliminary X-ray structural analysis, it is found that the structure of the material is monoclinic. In the study of the temperature dependence of the dielectric constant, the relaxor behaviour of the material is observed. Such type of behaviour is explained by a modified Curie-Weiss and a Vogel-Fulcher law. By analysing Nyquist plots, the existence of grain and grain boundary effects is established. The non-Debye type of relaxation is investigated by the analysis of complex impedance and the modulus data. From the study of impedance data, it is found that the grain resistance is reduced with the increase in temperature indicating the existence of negative temperature coefficient of resistance (NTCR) behaviour in the material which also matches with temperature versus AC conductivity plots. From these results, it may be concluded that this compound may have extreme potential for different high temperature applications.

scholarly journals Impedance spectroscopy studies on lead free (Ba0.85Ca0.15)(Ti0.9Zr0.1)O3 ceramics

2012 ◽  
Vol 6 (4) ◽  
pp. 201-207 ◽  
Author(s):  
Ahcène Chaouchi ◽  
Sadia Kennour
Keyword(s):  
High Temperature ◽  
Impedance Spectroscopy ◽  
Grain Boundary ◽  
Boundary Effect ◽  
Complex Impedance ◽  
Negative Temperature ◽  
Polycrystalline Sample ◽  
Impedance Analysis ◽  
Wide Frequency Range ◽  
Nyquist Plot

The AC complex impedance spectroscopy technique has been used to obtain the electrical parameters of polycrystalline sample of (Ba0.85Ca0.15) (Ti0.9Zr0.1)O3 in a wide frequency range at different temperatures. This sample was prepared by a high temperature solid-state reaction technique and single phase formation was confirmed by X-ray diffraction technique. This study was carried out by the means of simultaneous analysis of impedance, modulus, and electrical conductivity. The Cole-Cole (Nyquist) plots suggest that the grains and grain boundaries are responsible in the conduction mechanism of the material at high temperature. The Cole- Cole (Nyquist) plot studies revealed the presence of grain and grain boundary effect at 485 ?C. On the other hand, it showed only the presence of grain boundary component of the resistivity at 535 ?C. Complex impedance analysis indicated the presence of non-Debye type dielectric relaxation. The bulk resistance of the material decreases with rise in temperature similar to a semiconductor, and the Cole-Cole (Nyquist) plot showed the negative temperature coefficient of resistance (NTCR) character of (Ba0.85Ca0.15 )(Ti0.9Zr0.1 )O3. The value of activation energy is found to be 0.7433 eV, which suggests that the conduction may be the result of defect and charge carriers present in the materials.

Electrical and Magnetic Properties of Pb0.8La0.2Fe0.1Cr0.1Ti0.8O3

2019 ◽  
Vol 201 (1) ◽  
pp. 43-54
Author(s):  
Amrita Nayak ◽  
S. K. Patri ◽  
P. L. Deepti ◽  
B. Behera
Keyword(s):  
Negative Temperature Coefficient ◽  
Negative Temperature ◽  
Polycrystalline Sample ◽  
Solid State Reaction Method ◽  
X Ray Diffraction ◽  
Orthorhombic Crystal ◽  
X Ray ◽  
Electrical And Magnetic Properties ◽  
Phase Transition Temperatures ◽  
Different Temperatures

The dielectric spectroscopy of a new ceramic material; Pb0.8La0.2Fe0.1Cr0.1Ti0.8O3 has been studied. The compound was prepared by solid-state reaction method. The structural study from X-ray diffraction technique shows the formation of polycrystalline sample with orthorhombic crystal system at room temperature. Dielectric property of this material has been characterized in the temperature range of 25–450°C and frequency range of 100 Hz – 1 MHz respectively. The phase transition temperatures were at two different temperatures for each frequency. The nature of ac conductivity shows the negative temperature coefficient of resistance type behavior of the material.

scholarly journals Complex Impedance Spectroscopic Properties of Ceramics

2008 ◽  
Vol 2008 ◽  
pp. 1-5 ◽  
Author(s):  
Praveen Khatri ◽  
Banarji Behera ◽  
V. Srinivas ◽  
R. N. P. Choudhary
Keyword(s):  
Electrical Transport ◽  
Complex Impedance ◽  
Negative Temperature ◽  
Polycrystalline Sample ◽  
Spectroscopic Properties ◽  
Wide Frequency Range ◽  
Transport Processes ◽  
Effect Of Temperature ◽  
Temperature Dependent ◽  
Impedance Parameters

The polycrystalline sample of was prepared by a high-temperature solid-state reaction technique. The effect of temperature on impedance parameters was studied using an impedance analyzer in a wide frequency range (  Hz). The real and imaginary parts of complex impedance trace semicircles in the complex plane. The temperature-dependent plots reveal the presence of both bulk and grain boundary effects above C. The bulk resistance of the material decreases with rise in temperature. This exhibits a typical negative temperature coefficient of resistance (NTCR) behavior of the material. The modulus analysis suggests a possible hopping mechanism for electrical transport processes of the material. The nature of variation of dc conductivity suggests the Arrhenius type of electrical conductivity.

Dielectric Behavior of Mechano-chemically Synthesized [(CH3NH3)3Bi2Br9]: A Lead Free Hybrid Perovskite

2021 ◽  
Author(s):  
Swagatalaxmi Pujaru ◽  
Priyabrata Sadhukhan ◽  
Basudev Ghosh ◽  
Arup Dhara ◽  
Sachindranath Das
Keyword(s):  
Impedance Spectroscopy ◽  
Complex Impedance ◽  
Negative Temperature ◽  
Dielectric Behavior ◽  
Lead Free ◽  
Published Data ◽  
Temperature Dependent ◽  
Microstructural Parameters ◽  
Hybrid Perovskite ◽  
Refinement Method

Abstract Lead free hybrid halide perovskite (CH3NH3)3Bi2Br9 has been successfully synthesized by mechano-chemical method. The microstructure analysis by Rietveld’s refinement method revealed that the crystal belongs to trigonal system with space group P3 ̅m1. The obtained microstructural parameters are well in agreement with the previously published data. Temperature-dependent ac conductivity, impedance spectroscopy, and complex dielectric properties have been investigated in detail. The negative temperature coefficient of resistance behaviour reveals the semiconducting nature of the materials. The complex impedance spectroscopy also supports the semiconducting nature of the sample with activation energy for conduction ~0.38 eV.

Low temperature dielectric properties and NTCR behavior of the BaFe0.5Nb0.5O3 double perovskite ceramic

2020 ◽  
Vol 22 (5) ◽  
pp. 2986-2998 ◽  
Author(s):  
Vijay Khopkar ◽  
Balaram Sahoo
Keyword(s):  
Dielectric Properties ◽  
Low Temperature ◽  
Temperature Coefficient ◽  
Negative Temperature Coefficient ◽  
Double Perovskite ◽  
Negative Temperature ◽  
Lead Free ◽  
Temperature Coefficient Of Resistance ◽  
Perovskite Ceramic

The microstructure and low-temperature dielectric properties of lead-free BaFe0.5Nb0.5O3 ceramics exhibiting a negative temperature coefficient of resistance behavior.

scholarly journals Anomalous electrical conduction and negative temperature coefficient of resistance in nanostructured gold resistive switching films

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
M. Mirigliano ◽  
S. Radice ◽  
A. Falqui ◽  
A. Casu ◽  
F. Cavaliere ◽  
...  
Keyword(s):  
Grain Boundaries ◽  
Temperature Coefficient ◽  
Resistive Switching ◽  
Electrical Conduction ◽  
Negative Temperature Coefficient ◽  
Negative Temperature ◽  
High Density ◽  
Gold Films ◽  
Temperature Coefficient Of Resistance ◽  
Nanostructured Gold

AbstractWe report the observation of non-metallic electrical conduction, resistive switching, and a negative temperature coefficient of resistance in nanostructured gold films above the electrical percolation and in strong-coupling regime, from room down to cryogenic temperatures (24 K). Nanostructured continuous gold films are assembled by supersonic cluster beam deposition of Au aggregates formed in the gas phase. The structure of the cluster-assembled films is characterized by an extremely high density of randomly oriented crystalline nanodomains, separated by grain boundaries and with a large number of lattice defects. Our data indicates that space charge limited conduction and Coulomb blockade are at the origin of the anomalous electrical behavior. The high density of extended defects and grain boundaries causes the localization of conduction electrons over the entire investigated temperature range.

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