scholarly journals Frequency and temperature dependence behaviour of impedance, modulus and conductivity of BaBi4Ti4O15 aurivillius ceramic

2014 ◽  
Vol 8 (3) ◽  
pp. 145-153 ◽  
Author(s):  
Tanmaya Badapanda ◽  
Ranjan Harichandan ◽  
Sudhasu Nayak ◽  
Avinna Mishra ◽  
Sahid Anwar
Keyword(s):  
Relaxation Times ◽  
Complex Impedance ◽  
Negative Temperature ◽  
Impedance Spectrum ◽  
Nyquist Plot ◽  
Dielectric Study ◽  
Complex Impedance Spectrum ◽  
Debye Relaxation ◽  
Positive Side ◽  
Different Temperatures

In this work, we report the dielectric, impedance, modulus and conductivity study of BaBi4Ti4O15 ceramic synthesized by solid state reaction. X-ray diffraction (XRD) pattern showed orthorhombic structure with space group A21am confirming it to be an m=4 member of the Aurivillius oxide. The frequency dependence dielectric study shows that the value of dielectric constant is high at lower frequencies and decreases with increase in frequency. Impedance spectroscopy analyses reveal a non-Debye relaxation phenomenon since relaxation frequency moves towards the positive side with increase in temperature. The shift in impedance peaks towards higher frequency side indicates conduction in material and favouring of the long rangemotion of mobile charge carriers. The Nyquist plot from complex impedance spectrum shows only one semicircular arc representing the grain effect in the electrical conduction. The modulus mechanism indicates the non-Debye type of conductivity relaxation in the material, which is supported by impedance data. Relaxation times extracted using imaginary part of complex impedance (Z??) and modulus (M??) were also found to follow Arrhenius law. The frequency dependent AC conductivity at different temperatures indicates that the conduction process is thermally activated. The variation of DC conductivity exhibits a negative temperature coefficient of resistance behaviour.

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.

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 Electrical conductivity and dielectric behaviour of nanocrystalline La0.6Gd0.1Sr0.3Mn0.75Si0.25O3

RSC Advances ◽  
2018 ◽  
Vol 8 (17) ◽  
pp. 9103-9111 ◽  
Author(s):  
Ah Dhahri ◽  
E. Dhahri ◽  
E. K. Hlil
Keyword(s):  
Electrical Conductivity ◽  
Equivalent Circuit ◽  
Complex Impedance ◽  
Impedance Spectrum ◽  
Dielectric Behaviour ◽  
Complex Impedance Spectrum ◽  
Electrical Equivalent Circuit ◽  
Different Temperatures

A complex impedance spectrum for La0.6Gd0.1Sr0.3Mn0.75Si0.25O3 sample at different temperatures with electrical equivalent circuit.

scholarly journals Dielectric relaxation and modulus spectroscopy analysis of (Na0.47 K0.47 Li0.06) NbO3 ceramics

2017 ◽  
Vol 07 (03) ◽  
pp. 1750020 ◽  
Author(s):  
Md Kashif Shamim ◽  
Seema Sharma ◽  
Sangeeta Sinha ◽  
Eqra Nasreen
Keyword(s):  
Dielectric Relaxation ◽  
Spectroscopic Analysis ◽  
Microwave Sintering ◽  
Complex Impedance ◽  
Tungsten Bronze ◽  
Negative Temperature ◽  
Nyquist Plot ◽  
Orthorhombic Symmetry ◽  
Modulus Spectroscopy ◽  
C Complex

We have investigated the structure, dielectric and electrical properties of lead-free polycrystalline (Na[Formula: see text] K[Formula: see text] Li[Formula: see text]) NbO3 ceramics as a function of temperature and frequency in order to understand the intrinsic contribution of grain/bulk and grain boundary effects toward the dielectric response as well as the electrical conduction mechanism in the samples fabricated by microwave sintering method. X-ray diffraction analysis exhibits perovskite structure with orthorhombic symmetry, which is well supported by the Raman spectroscopic analysis. A minor secondary impurity phase of tungsten bronze structure was observed for samples sintered at 1050[Formula: see text]C, which gets weaker for samples sintered at 1150[Formula: see text]C. Dielectric permittivity was enhanced by 50%, although there was a reduction in the dielectric loss by about 50% at Curie temperature (450[Formula: see text]C) for samples sintered at 1150[Formula: see text]C. Complex impedance spectroscopic analysis indicated non-Debye-type dielectric relaxation present in the samples, and this phenomenon followed thermally activated process related to hopping mechanism. Nyquist plot showed the negative temperature coefficient of resistance, characteristic of the samples.

scholarly journals Микроволновая вольт-импедансная спектроскопия полупроводников

2020 ◽  
Vol 90 (11) ◽  
pp. 1944
Author(s):  
А.Н. Резник ◽  
Н.В. Востоков ◽  
Н.К. Вдовичева ◽  
В.И. Шашкин
Keyword(s):  
Electrical Potential ◽  
Complex Impedance ◽  
Impedance Spectrum ◽  
Antenna System ◽  
Electrical Potential Difference ◽  
Complex Impedance Spectrum ◽  
Homogeneous Sample ◽  
Semiconductor Interface ◽  
Constant Bias ◽  
Central Disk

We have tested experimentally the proposed method of microwave volt-impedance spectroscopy of semiconductors. The method allows to determine the local values of the semiconductor electrophysical parameters. The studies were performed on a homogeneous single-crystal GaAs wafer with a concentric antenna system formed on its surface. The resolution is determined by the diameter of the antenna central disk, which was amounted a = 12, 27, 57 μm. A constant bias voltage of 0 ≤ U ≤ 5 V was applied between the contact pads of the antennas. The complex impedance spectrum Z (f, U) of each antenna was measured using a Cascade Microtech probe station in the frequency range f = 0.1 - 10 GHz. The electrophysical characteristics of the semiconductor were determined from Z(f, U) spectra by the inverse problem solving. We have established the n-type for our semiconductor and determined the electrical potential difference on the metal-semiconductor interface. We have found as well the electron concentration, mobility and conductivity. Measurements of the same parameters by Hall four-probe method (giving the surface averaging) showed good mutual agreement of the results for the homogeneous sample under study.

scholarly journals Effect of Microwave Sintering on Electrical Properties of Sr-deficient and Bi-rich Strontium Bismuth Niobate (Sr0.8Bi2.2Nb2O9) Ferroelectric Ceramic

2016 ◽  
Vol 1 (1) ◽  
pp. 35-45 ◽  
Author(s):  
RAJVEER SINGH ◽  
Vandna Luthra ◽  
Ram Pal Tandon
Keyword(s):  
Conduction Mechanism ◽  
Microwave Sintering ◽  
Complex Impedance ◽  
Negative Temperature ◽  
Ferroelectric Ceramic ◽  
Relaxation Mechanism ◽  
Bulk Resistance ◽  
Conventional Solid State Reaction ◽  
Debye Relaxation ◽  
Bismuth Niobate

Nonstoichiometric strontium bismuth niobate (Sr0.8Bi2.2Nb2O9: SBN) ceramic was prepared using conventional solid-state reaction and microwave sintering methods. Complex impedance spectroscopy (CIS) has been used to investigate the intra and intergranular contribution to the impedance SBN ceramics as a function of temperature and frequency. Complex impedance Cole‑Cole plots were used to interpret the relaxation mechanism in SBN ceramic which showed a non-Debye relaxation. The grain and grain boundary contribution to conductivity have been estimated from the Cole‑Cole plots. The bulk (grain) resistance of both samples was found to decrease with rise in temperature indicating negative temperature coefficient of resistance (NTCR) type behavior like that of semiconductors. The microwave sintered SBN was found to have low value of bulk resistance indicating more increase in conductivity as compared to conventionally sintered SBN. The temperature dependence of the relaxation time was found to obey the Arrhenius law. Studies of electrical modulus show the presence of hoping conduction mechanism in SBN.

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 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.

scholarly journals Study of the structural and electrical behavior of Bi(Mg,Ti)O3 modified (Ba,Ca)TiO3 ceramics

2016 ◽  
Vol 06 (04) ◽  
pp. 1650035 ◽  
Author(s):  
Md. Kashif Shamim ◽  
Seema Sharma ◽  
Arpana Singh ◽  
Radheshyam Rai ◽  
Rashmi Rani
Keyword(s):  
Spectroscopic Study ◽  
Perovskite Phase ◽  
Base Material ◽  
Negative Temperature ◽  
Ferroelectric Material ◽  
Nyquist Plot ◽  
Lead Free ◽  
Dielectric Study ◽  
Raman Spectroscopic ◽  
Structural And Electrical Properties

The ability of BaTiO3 to form solid solutions with different dopants (both iso- and aliovalent) makes it versatile for various applications. In the present study, (Ba,Ca)TiO3 (BCT) is modified with Bi(MgTi)O3 (BMT) in search for new lead-free ferroelectric material and improve their properties. For this purpose, BCT acts as a main base material and BMT acts as a modifier to fabricate a multifunctional material. In this study, we report the structural and electrical properties of lead free piezo-ceramics ([Formula: see text])(Ba[Formula: see text]Ca[Formula: see text])TiO3–[Formula: see text]Bi(Mg[Formula: see text]Ti[Formula: see text])O3 with [Formula: see text], 0.4, 0.5 prepared by solid-state sintering technique. Single perovskite phase with tetragonal structure is obtained for all the compositions, which is reconfirmed by the Raman Spectroscopic study. Dielectric study confirm the temperature stable behavior of the dielectric permittivity values above 300[Formula: see text]C. The dielectric constant value decreases with increase in BMT doping content. Impedance Spectroscopic study confirms non-Debye type dielectric relaxation in the specimen. The Nyquist plot and conductivity studies show the negative temperature coefficient of resistance behavior (NTCR) of the samples.

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