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

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.

2016 ◽  
Vol 10 (1) ◽  
pp. 47-55 ◽  
Author(s):  
Kotamalige Anand ◽  
Bhajanthri Ramamurthy ◽  
Valaparla Veeraiah ◽  
Kannipamula Babu

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.


2010 ◽  
Vol 17 (01) ◽  
pp. 27-32 ◽  
Author(s):  
SANG-HO MOON ◽  
YONG-SU HAM ◽  
JUNG-HYUK KOH

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.


RSC Advances ◽  
2015 ◽  
Vol 5 (3) ◽  
pp. 2177-2184 ◽  
Author(s):  
M. Smari ◽  
H. Rahmouni ◽  
N. Elghoul ◽  
I. Walha ◽  
E. Dhahri ◽  
...  

The electric and dielectric properties of La0.5Ca0.5−xAgxMnO3 (LCMO–Ag with x = 0 and x = 0.4) were investigated using the impedance spectroscopy technique.


2013 ◽  
Vol 699 ◽  
pp. 490-495
Author(s):  
Ramna Tripathi ◽  
Akhilesh Kumar

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.


2007 ◽  
Vol 21 (06) ◽  
pp. 931-945 ◽  
Author(s):  
K. SAMBASIVA RAO ◽  
P. MURALI KRISHNA ◽  
D. MADHAVA PRASAD ◽  
JOON HYUNG LEE

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.


2020 ◽  
Vol 34 (06) ◽  
pp. 2050081
Author(s):  
Subrat Kumar Barik ◽  
A. R. Atique Ulla

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.


2012 ◽  
Vol 02 (03) ◽  
pp. 1250008 ◽  
Author(s):  
B. PARIJA ◽  
S. PANIGRAHI ◽  
T. BADAPANDA ◽  
T. P. SINHA

We report the temperature and frequency dependence impedance spectroscopy of (1 - x) ( Bi 0.5 Na 0.5) TiO 3-x BaTiO 3 (abbreviated as BNT–BT) ceramics with 0 ≤ x ≤ 0.07 prepared by conventional solid-state route. X-ray diffraction analysis indicated that a solid solution is formed when BaTiO3 diffuses into the (Bi0.5Na0.5)TiO3 lattice and a morphotropic phase boundary between rhombohedral and tetragonal locates at x = 0.07. The microstructure indicated that the grain size reduces and the shape changes from rectangular to quasi-spherical with increase in BaTiO3 content. Complex Impedance Spectroscopy analysis suggested the presence of temperature-dependent relaxation process in the materials. The modulus mechanism indicated the non-Debye type of conductivity relaxation in the materials, which is supported by impedance data. The activation energies have been calculated from impedance, electric modulus studies and dc conductivity which suggests that the conductions are ionic in nature. The activation energy increases with increase of BT content up to x = 0.05 and decreases at x = 0.07 which also indicates the presence of morphotropic phase boundary at x = 0.07.


2012 ◽  
Vol 02 (03) ◽  
pp. 1250015
Author(s):  
S. K. PATRI ◽  
R. N. P. CHOUDHARY ◽  
C. RINALDI

Bi 9-x Fe 5+x Ti 3 O 27 (x = 0-3) compounds of bismuth layered perovskite structure have been successfully prepared by solid-state reaction method. X-ray diffraction (XRD) studies revealed the orthorhombic crystal structure of all the compounds. Impedance spectroscopy has been studied to characterize the electrical properties of polycrystalline Bi 9-x Fe 5+x Ti 3 O 27 (x = 0-3) compounds. The shape of complex impedance curves inferred the contribution of bulk and grain boundary effects on the electrical properties of the compounds. Temperature dependent magnetization measurements were made from 2 K to 300 K. Narrow hysteresis loops observed at room temperature indicate antiferromagnetic behavior of the compounds.


2019 ◽  
Vol 16 (4) ◽  
pp. 477-486
Author(s):  
Atif Alkhazali ◽  
Morad Etier ◽  
Mohammad Aljarrah ◽  
Akram Alsukker ◽  
Fathy Salman

Purpose The purpose of this study is to investigate the effect of the considerable Ag2SO4 content on the electrical and dielectric properties of (AgPO3)1−x(Ag2SO4)x ion glass system as well as to extract thermodynamic parameters. Design/methodology/approach Glass samples of (AgPO3)1-x(Ag2SO4)x with different mole ratios of Ag2SO4 [x = 0.00, 0.10,0.15,0.20 and 0.25] have been synthesized and used. X-ray diffraction and differential thermal analysis were used to investigate structural and thermal properties, and then the electrical characterizations of the bulk glasses were performed in different frequency and temperature range. Findings For different ratios of Ag2SO4 on AgPO3, the bulk conductivity is enhanced with increasing the amount of Ag2SO4 until the composition of x = 0.20, after which the conductivity decreases. The general behavior of both ε’ and ε” decreases with increasing frequency and increases with increasing temperature. Complex impedance analysis studied by Z‘−Z’ and Cole–Cole plot at different temperatures revealed that bulk resistance decreases with temperature. Originality/value The calculated values of activation free energy, enthalpy and entropy change for different compositions of (AgPO3)1-x(Ag2SO4)x showed an increase in activation energy and enthalpy when Ag2SO4 ratio is increased in (AgPO3)1-x(Ag2SO4)x composition up to 20%, and then there is a decrease in their values at x = 25%, which may be explained based on non-bridging oxygen.


2015 ◽  
Vol 05 (01) ◽  
pp. 1550007 ◽  
Author(s):  
M. Saidi ◽  
A. Chaouchi ◽  
S. D'Astorg ◽  
M. Rguiti ◽  
C. Courtois

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.


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