COMPLEX IMPEDANCE SPECTROSCOPY ON ZnO-B2O3 DOPED (Ba, Sr)TiO3 CERAMICS

2010 ◽  
Vol 17 (01) ◽  
pp. 27-32 ◽  
Author(s):  
SANG-HO MOON ◽  
YONG-SU HAM ◽  
JUNG-HYUK KOH
Keyword(s):  
Impedance Spectroscopy ◽  
Complex Impedance ◽  
Negative Temperature ◽  
Nyquist Plot ◽  
X Ray Diffraction ◽  
X Ray ◽  
Different Temperatures ◽  
Bst Ceramics ◽  
Grain Growth Behavior ◽  
Microscopy Images

BST ceramics with doping of 1, 3, and 5 wt.% ZnBO were prepared by the conventional mixed oxide method and sintered at 1100°. X-ray diffraction analyses were carried out to verify the structural properties. 1, 3, and 5 wt.% ZnBO doped BST ceramics were crystallized with weak tetragonal structure at 1100°C. The grain growth behavior and shapes were investigated by scanning electron microscopy images. The electrical properties of 1, 3, and 5 wt.% ZnBO doped BST ceramics were investigated by impedance spectroscopy at the different temperatures (350, 375, and 400°C). Impedance spectroscopy data presented in Nyquist plot show the existence of both grain and grain boundary effects in all specimens. 1, 3, and 5 wt.% ZnBO doped BST ceramics showed negative temperature coefficient of resistance (NTCR). Also, the capacitances and resistances of grains and grain boundaries for 1, 3, and 5 wt.% doped BST ceramics were simulated through equivalent circuit with the parallelly connected capacitors and resistors. The capacitance and resistance were decreased when temperature and ZnBO dopants were increased.

scholarly journals Dielectric, ferroelectrics properties and impedance spectroscopy analysis of the [(Na0.535K0.480)0.966Li0.058](Nb0.90Ta0.10)O3-based lead-free ceramics

2015 ◽  
Vol 05 (01) ◽  
pp. 1550007 ◽  
Author(s):  
M. Saidi ◽  
A. Chaouchi ◽  
S. D'Astorg ◽  
M. Rguiti ◽  
C. Courtois
Keyword(s):  
Complex Impedance ◽  
Negative Temperature ◽  
Impedance Analysis ◽  
Xrd Analysis ◽  
Ac Impedance ◽  
Nyquist Plot ◽  
X Ray Diffraction ◽  
Complex Impedance Analysis ◽  
Lead Free Ceramics ◽  
Different Temperatures

Polycrystalline of [( Na 0.535 K 0.480)0.966 Li 0.058] (Nb 0.90 Ta 0.10) O 3 samples were prepared using the high-temperature solid-state reaction technique. X-ray diffraction (XRD) analysis indicates the formation of a single-phase with orthorhombic structure. AC impedance plots were used as tool to analyze the electrical behavior of the sample as a function of frequency at different temperatures. The AC impedance studies revealed the presence of grain effect, from 425°C onwards. Complex impedance analysis indicated non-Debye type dielectric relaxation. The Nyquist plot showed the negative temperature coefficient of resistance (NTCR) characteristic of NKLNT. The AC conductivity results were used to correlate with the barrier hopping (CBH) model to evaluate the binding energy (Wm), the minimum hopping distance (R min ), the density of states at Fermi level (N(Ef)), and the activation energy of the compound.

Characterization, Optical and Impedance Study of ZnSe Nanostructure

2013 ◽  
Vol 699 ◽  
pp. 490-495
Author(s):  
Ramna Tripathi ◽  
Akhilesh Kumar
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Impedance Spectroscopy ◽  
Zinc Selenide ◽  
Relaxation Times ◽  
Complex Impedance ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
The Stability

Zinc selenide nanoparticle has been synthesized using soft chemical routes. The particles were capped using 2-mercaptoethanol to achieve the stability and avoid the coalescence. The as-obtained particles were characterized by X-ray diffraction (XRD), Transmission electron microscopy (TEM), UV–VIS absorption and photoluminescence (PL) spectra. The impedance studies were carried out as a function of frequency (100 Hz–1 MHz) and temperature (298–373 K) by impedance spectroscopy. An analysis of the complex impedance (z' and z") with frequency is performed assuming a distribution of relaxation times.

INFLUENCE OF SAMARIUM SUBSTITUTION ON IMPEDANCE DIELECTRIC AND ELECTROMECHANICAL PROPERTIES OF Pb(1-x)K2xNb2O6

2007 ◽  
Vol 21 (06) ◽  
pp. 931-945 ◽  
Author(s):  
K. SAMBASIVA RAO ◽  
P. MURALI KRISHNA ◽  
D. MADHAVA PRASAD ◽  
JOON HYUNG LEE
Keyword(s):  
Impedance Spectroscopy ◽  
Room Temperature ◽  
Single Phase ◽  
Piezoelectric Properties ◽  
Orthorhombic Structure ◽  
X Ray Diffraction ◽  
Electromechanical Properties ◽  
X Ray ◽  
Different Temperatures ◽  
Ferroelectric Hysteresis

Ferroelectric, hysteresis, impedance spectroscopy parameters, AC conductivity, and piezoelectric properties in the ceramics of Pb 0.74 K 0.52 Nb 2 O 6 and Pb 0.74 K 0.13 Sm 0.13 Nb 2 O 6 have been studied. X-ray diffraction study reveals single phase with the orthorhombic structure. The samples were characterized for ferroelectric and impedance spectroscopy properties from room temperature to 600°C. Cole–Cole plots (Z″ versus Z′) are drawn at different temperatures. The results obtained are analyzed to understand the conductivity mechanism in both the samples. The piezoelectric constant d33 has been found to be 96 × 10-12 C/N in PKN.

scholarly journals Structural, Dielectric, Magnetic and Magneto-Dielectric Properties of (1-x)BiFeO3–(x)CaTiO3 Composites

2021 ◽  
Author(s):  
Bushra Khan ◽  
Aditya Kumar ◽  
Preeti Yadav ◽  
Gulab Singh ◽  
Ashok Kumar ◽  
...  
Keyword(s):  
Ac Conductivity ◽  
Sol Gel ◽  
Negative Temperature ◽  
Tangent Loss ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structure Changes ◽  
Different Temperatures ◽  
Ferromagnetic Ordering ◽  
Jonscher’S Power Law

Abstract (1-x) BiFeO3–(x) CaTiO3 [(1-x) BFO – (x) CTO, (x = 0, 0.1, 0.2 and 0.3)] composites were synthesized using sol-gel chemical rout method. X-ray diffraction investigation shows the crystal structure changes from rhombohedral to monoclinic for 0 ≤ x ≤ 0.2, and it changes to orthorhombic at x ≤ 0.3. The Field Emission Scanning Electron Microscope (FESEM) investigation confirms the the microstructure consists of randomly oriented, homogenous, and non-uniform grains. The dielectric permittivity (ε) and tangent loss (tanδ) decreases with increasing frequency and show dielectric anomalies (as a hump) at different temperatures for different compositions. The incorporation of CTO, decreases three order of leakage current (up to x = 0.2) and significantly improve the magnetization and magneto-dielectric coupling. The frequency-dependent ac conductivity obeys Jonscher’s power law with large ac conductivity dispersion for higher frequencies with increasing CTO concentration. The variations of ac conductivity with the inverse of temperature obey the Arrhenius equation and show negative temperature coefficient of resistance (NTCR) behavior. The ferromagnetic (FM) properties in BFO-CTO increases significantly with an increase of the CTO concentration. The coercive field increases with increasing CTO concentration suggesting a competition between the antiferromagnetic and ferromagnetic ordering. At room temperature, all the samples show strong magneto-dielectric coupling.

Relaxation mechanism and conductivity studies of lead-free ceramics: Fe1/2(NaLi)1/4TiO3

2020 ◽  
Vol 34 (06) ◽  
pp. 2050081
Author(s):  
Subrat Kumar Barik ◽  
A. R. Atique Ulla
Keyword(s):  
Complex Impedance ◽  
Negative Temperature ◽  
Relaxation Mechanism ◽  
Lead Free ◽  
X Ray Diffraction ◽  
Prepared Sample ◽  
Lead Free Ceramics ◽  
Wide Range ◽  
Different Temperatures ◽  
Energy Formula

A single-phase lead-free ferroelectric compound, Fe[Formula: see text](NaLi)[Formula: see text]TiO3, is found at room temperature. The solid state reaction technique helps to process the sample at the calcination and sintering temperatures of 900 and 950[Formula: see text][Formula: see text]C for 4 h respectively. The desired phase and crystal structure formation of the prepared sample are confirmed by analysis of X-ray diffraction (XRD) data and are found to be in orthorhombic structure. The correlation among phase formation and physical properties has been established by using complex impedance spectroscopy (CIS) method over a wide range of frequencies (from 100 Hz to 1 MHz) and different temperatures (25–280[Formula: see text][Formula: see text]C). The overlap depressed semicircular arcs represent the association of grain and grain boundary effects in the material. Activation energy [Formula: see text] is noted to be 1 eV for the prepared sample. The frequency dependent ac conductivity is followed by Jonscher’s universal power law. DC conductivity versus temperature graph also indicates the negative temperature coefficient of resistance (NTCR) behavior of the material.

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.

scholarly journals Structural, dielectric and conductivity studies of LiNi0.75Mg0.25-xCuxPO4 synthesized by solid state reaction method

2016 ◽  
Vol 10 (1) ◽  
pp. 47-55 ◽  
Author(s):  
Kotamalige Anand ◽  
Bhajanthri Ramamurthy ◽  
Valaparla Veeraiah ◽  
Kannipamula Babu
Keyword(s):  
Solid State ◽  
Impedance Spectroscopy ◽  
Solid State Reaction ◽  
Complex Impedance ◽  
Solid State Reaction Method ◽  
X Ray Diffraction ◽  
Reaction Method ◽  
Different Temperatures ◽  
Impedance Spectroscopy Technique ◽  
Ftir Technique

The olivine structured LiNi0.75Mg0.25-xCuxPO4 (x = 0, 0.05 and 0.1) cathode materials were synthesized by solid state reaction method. The XRD, FTIR and FESEM studies were conducted to investigate the phase purity, crystal structure, lattice parameters and morphology, respectively. The powder X-ray diffraction studies confirmed the single phase formation of the pure and doped compounds which are found to be orthorhombic with the parent LiNiPO4. Morphology and grain sizes of the materials were investigated through FESEM. The FTIR technique was used to characterize the stretching and bending vibrational modes of different functional groups existing in the materials. The cathode properties were analysed through impedance spectroscopy and indicated on improved electrical properties of the doped samples as compared to the pure LiNiPO4. The conductivity and modulus analyses of the samples were carried out at different temperatures and frequencies using the complex impedance spectroscopy technique.

scholarly journals Electrical, dielectric properties and study of AC electrical conduction mechanism of Li 0.9 □ 0.1 NiV 0.5 P 0.5 O 4

2018 ◽  
Vol 5 (2) ◽  
pp. 171472 ◽  
Author(s):  
A. Rahal ◽  
S. Megdiche Borchani ◽  
K. Guidara ◽  
M.  Megdiche
Keyword(s):  
Impedance Spectroscopy ◽  
Conduction Mechanism ◽  
Small Polaron ◽  
Parent Compound ◽  
Complex Impedance ◽  
X Ray Diffraction ◽  
Different Temperatures ◽  
Impedance Spectroscopy Technique ◽  
Olivine Structure ◽  
Lithium Deficiency

In this paper, we report the measurements of impedance spectroscopy for a new olivine-type lithium deficiency Li 0.9 □ 0.1 NiV 0.5 P 0.5 O 4 compound. It was synthesized by the conventional solid-state technique. All the X-ray diffraction peaks of the compound are indexed, and it is found that the sample is well crystallized in orthorhombic olivine structure belonging to the space group Pnma . Conductivity and dielectric analyses of the sample are carried out at different temperatures and frequencies using the complex impedance spectroscopy technique. The electrical conductivity of Li 0.9 □ 0.1 NiV 0.5 P 0.5 O 4 is higher than that of parent compound LiNiV 0.5 P 0.5 O 4 . Temperature dependence of the DC conductivity and modulus was found to obey the Arrhenius law. The obtained values of activation energy are different which confirms that transport in the title compound is not due to a simple hopping mechanism. To determine the conduction mechanism, the AC conductivity and its frequency exponent have been analysed in this work by a theoretical model based on quantum mechanical tunnelling: the non-overlapping small polaron tunnelling model.

scholarly journals Investigation of complex impedance and modulus properties of Nd doped 0.5BiFeO3-0.5PbTiO3 multiferroic Composites

Open Physics ◽  
2014 ◽  
Vol 12 (12) ◽  
Author(s):  
Ajay Behera ◽  
Nilaya Mohanty ◽  
Santosh Satpathy ◽  
Banarji Behera ◽  
Pratibindhya Nayak
Keyword(s):  
Electrical Transport ◽  
Complex Impedance ◽  
Negative Temperature ◽  
Nyquist Plot ◽  
X Ray Diffraction ◽  
Solid State Reaction Technique ◽  
Impedance Plot ◽  
Increasing Temperature ◽  
Modulus Studies ◽  
Conductivity Spectra

Abstract0.5BiNdxFe1−x O 3 − 0.5PbTiO3 (BNxF1−x − PT)(x = 0.05, 0.10, 0.15, 0.20) composites were successfully synthesized by a solid state reaction technique. At room temperature, X-ray diffraction shows tetragonal structure for all concentrations of Nd doped 0.5BiFeO3 − 0.5PbTiO3 composites. The nature of Nyquist plot confirms the presence of bulk effects only for BNxF1−x − PT (x = 0.05, 0.10, 0.15, 0.20) composites. The bulk resistance is found to decreases with the increasing temperature as well as Nd concentration and exhibits a typical negative temperature coefficient of resistance (NTCR) behavior. Both the complex impedance and modulus studies have suggested the presence of non-Debye type of relaxation in the composites. Conductivity spectra reveal the presence of hopping mechanism in the electrical transport process of the composites. The activation energy calculated from impedance plot of the composite decreases with increasing Ndx concentration and found to be 0.89, 0.76, 0.71 and 0.70 eV for x=0.05, 0.10, 0.15 and 0.20 respectively.

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.

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