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 Comprehensive investigation of structural, dielectric and local piezoelectric properties of KNN ceramics

2019 ◽  
Vol 09 (02) ◽  
pp. 1950016 ◽  
Author(s):  
Poonam Kumari ◽  
Madan Lal ◽  
Sunil Kumar ◽  
Radheshyam Rai ◽  
Anupinder Singh ◽  
...  
Keyword(s):  
Negative Temperature Coefficient ◽  
Piezoelectric Properties ◽  
Negative Temperature ◽  
Solid State Reaction Method ◽  
X Ray Diffraction ◽  
Temperature Coefficient Of Resistance ◽  
X Ray ◽  
Ceramic Samples ◽  
Free Ion ◽  
Diffraction Patterns

In this research paper, we utilized the traditional high-temperature solid-state reaction method to fabricate the K[Formula: see text]Na[Formula: see text]NbO3, K[Formula: see text]Na[Formula: see text]NbO3 and K[Formula: see text]Na[Formula: see text]NbO3 (abbreviated as KNN-1, KNN-2, and KNN-3, respectively) lead-free ion deficient ceramics for understanding the influence of ionic deficiency on the crystalline structure and dielectric/piezoelectric properties of the samples. X-ray diffraction patterns of these samples exhibited a perovskite tetragonal phase. Dielectric anomalies around 287∘C and 471∘C were identified as ferroelectric to ferroelectric and ferroelectric to paraelectric-transition temperatures for KNN-2 at 1[Formula: see text]kHz. It was found that the composition KNN-2 exhibit relatively high Curie temperature i.e., 471∘C. The conductivity plots confirm that the activation energies are frequency-dependent. The impedance behavior in our ceramic samples can be analyzed with the bulk/grain effect. The slope of [Formula: see text] with temperature shows negative temperature coefficient of resistance (NTCR) type behavior in proposed KNN ceramics material.

scholarly journals Influence of Li2CO3 addition on electrical and magnetic properties of Ni0.6Mg0.4Fe2O4

2020 ◽  
Vol 10 (03) ◽  
pp. 2050003
Author(s):  
M. R. Hassan ◽  
M. T. Islam ◽  
M. N. I. Khan
Keyword(s):  
Magnetic Properties ◽  
Single Phase ◽  
Low Frequency ◽  
Solid State Reaction Method ◽  
Charge Carriers ◽  
X Ray Diffraction ◽  
X Ray ◽  
Electrical And Magnetic Properties ◽  
Frequency Regime ◽  
Xrd Patterns

In this research, influence of adding Li2CO3 (at 0%, 2%, 4%, 6%) on electrical and magnetic properties of [Formula: see text][Formula: see text]Fe2O4 (with 60% Ni and 40% Mg) ferrite has been studied. The samples are prepared by solid state reaction method and sintered at 1300∘C for 6[Formula: see text]h. X-ray diffraction (XRD) patterns show the samples belong to single-phase cubic structure without any impurity phase. The magnetic properties (saturation magnetization and coercivity) of the samples have been investigated by VSM and found that the higher concentration of Li2CO3 reduces the hysteresis loss. DC resistivity increases with Li2CO3 contents whereas it decreases initially and then becomes constant at lower value with temperature which indicates that the studied samples are semiconductor. The dielectric dispersion occurs at a low-frequency regime and the loss peaks are formed in a higher frequency regime, which are due to the presence of resonance between applied frequency and hopping frequency of charge carriers. Notably, the loss peaks are shifted to the lower frequency with Li2CO3 additions.

Structural, Dielectric and Electrical Studies of Ba4CaRTi3Nb7O30 (R = Eu, Dy) Ferroelectric System

2013 ◽  
Vol 547 ◽  
pp. 41-48 ◽  
Author(s):  
Prasun Ganguly ◽  
A.M. Biradar ◽  
A.K. Jha
Keyword(s):  
Single Phase ◽  
Microstructural Analysis ◽  
Tungsten Bronze ◽  
Negative Temperature ◽  
Xrd Analysis ◽  
Solid State Reaction Method ◽  
X Ray Diffraction ◽  
Orthorhombic Crystal ◽  
Paraelectric Phase Transition ◽  
Orthorhombic Crystal Structure

The polycrystalline samples of Ba4CaRTi3Nb7O30 (R = Eu, Dy), members of tungsten-bronze family, were prepared by high-temperature solid state reaction method and studied for their dielectric and electrical properties. X-ray diffraction (XRD) analysis reveals the formation of single-phase compounds having orthorhombic crystal structure at room temperature. Microstructural analysis by scanning electron microscope (SEM) shows that the compounds have well defined grains, which are distributed uniformly throughout the sample. Detailed dielectric properties of the compounds as a function of frequency and temperature show that the compounds undergo non-relaxor kind of ferroelectric-paraelectric phase transition of diffuse nature. Ferroelectric, piezoelectric and pyroelectric studies of the compounds have been discussed in this paper. The temperature dependence of dc conductivity of the compounds have been investigated. The conductivity study over a wide temperature range suggests that the compounds have negative temperature coefficient of resistance (NTCR) behaviour.

Aging of iron manganite negative temperature coefficient thermistors

1998 ◽  
Vol 13 (5) ◽  
pp. 1238-1242 ◽  
Author(s):  
T. Battault ◽  
R. Legros ◽  
A. Rousset
Keyword(s):  
Temperature Coefficient ◽  
Spinel Structure ◽  
Negative Temperature Coefficient ◽  
Negative Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Octahedral Sites ◽  
Before And After ◽  
Structural Equilibrium ◽  
Electrical Data

“Aging,” defined as the drift of resistance with temperature after 1000 h, was investigated for iron manganite temperature coefficient thermistors. For these devices, aging is relatively large, about 10%. The cationic distributions before and after aging were determined by Mössbauer spectroscopy. These distributions explain all the x-ray diffraction and correlated electrical data. The origin of the aging observed on iron manganites thermistors has been identified. It is due to the migration of Fe3+ ions from tetrahedral to octahedral sites of the spinel structure in order to reach a structural equilibrium.

Thermal enhancement of 2H11/2→4I15/2 up-conversion luminescence of Er3+ doped K2Yb(PO4)(MoO4) phosphors

2021 ◽  
Author(s):  
Hongqiang Cui ◽  
Yongze Cao ◽  
Lei Zhang ◽  
Yuhang Zhang ◽  
Siying Ran ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Solid State Reaction ◽  
Solid State Reaction Method ◽  
X Ray Diffraction ◽  
Orthorhombic Crystal ◽  
Orthorhombic Crystal Structure ◽  
Reaction Method ◽  
X Ray ◽  
Thermal Enhancement

Er3+ with different concentrations doped K2Yb(PO4)(MoO4) phosphors were prepared by a solid-state reaction method, and the layered orthorhombic crystal structure of the samples was confirmed by X-ray diffraction (XRD). Under...

Luminescence Behavior of Tm3+ Activated GdAlO3 Phosphors Synthesized Using Solid-Reaction Method

2014 ◽  
Vol 602-603 ◽  
pp. 32-37 ◽  
Author(s):  
Nan Wu ◽  
Xiao Dong Li ◽  
Shao Hong Liu ◽  
Yu Dong ◽  
Ji Guang Li ◽  
...  
Keyword(s):  
Decay Curve ◽  
Exchange Interactions ◽  
Solid State Reaction Method ◽  
X Ray Diffraction ◽  
Nanosized Powders ◽  
Reaction Method ◽  
X Ray ◽  
Pure Phase ◽  
Different Temperatures ◽  
High Color Purity

Trivalent thulium ions (Tm3+) doped GdAlO3 (Gd1-xTmxAlO3) phosphors which show a blue luminescence of high color purity have been synthesized by using solid-state reaction method starting from nanosized powders. X-ray diffraction (XRD) measurements were used to analyze the phase transformations that take place during the preparation of the phosphors. The morphologies of the powders calcined at different temperatures were studied by using scanning electron microscopy (SEM). The luminescence properties of the compounds were investigated. Pure phase of orthorhombic type GdAlO3 (GAP) was yielded by calcining the phosphors at 1200°C for 8 h. The PL spectra showed representative Tm3+ emission. The strong band centered at ~488 nm and the weak one centered at 697 nm were attributed to the 1D2-3F4 and 1G4-3F4 transitions of Tm3+, respectively. The quenching concentration of Tm3+ was estimated to be ~0.75at.% (x=0.0075), for which can be ascribed to the exchange interactions. The decay curve was fitted to be a single exponent and the estimated fluorescent lifetime of the GdAlO3:Tm3+ phosphor was 1.73±0.08 ms.

Electrical Studies on PZT Ceramic

2012 ◽  
Vol 560-561 ◽  
pp. 816-819
Author(s):  
N.V. Prasad ◽  
B. Ramaiah ◽  
V. Nathanial ◽  
M. Chandra Sekhar
Keyword(s):  
Oxygen Vacancies ◽  
Single Phase ◽  
Polycrystalline Sample ◽  
Solid State Reaction Method ◽  
Electrical Behavior ◽  
Conduction Model ◽  
X Ray ◽  
Electrical Studies ◽  
Different Temperatures ◽  
And Migration

Polycrystalline sample of PZT (52/48) was prepared by solid-state reaction method. X-ray analysis indicated the formation of single-phase. Electrical and impedance-spectroscopy plots were employed to analyze the electrical behavior of the sample, as a function of frequency, in the range of 0.01 Hz to 1 M Hz at different temperatures. Spectroscopic and complex plots indicated non-Debye dielectric relaxation. Detailed electrical studies revealed that the conduction is through hoping of electrons (extrinsic region) at lowers temperature and migration of oxygen vacancies at high temperature (intrinsic region). The results are explained using Euryod’s conduction model and confirmed with pyroelectric and ferroelectric data.

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 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.

Preparation and Characterizations of Novel Near Room-Temperature Driven Fe/Sr2Bi2O5 Thermocatalyst

2014 ◽  
Vol 804 ◽  
pp. 63-66
Author(s):  
Pei Wu ◽  
Xue Gang Luo ◽  
Xiao Yan Lin ◽  
Ke Li
Keyword(s):  
Room Temperature ◽  
Negative Temperature Coefficient ◽  
Removal Rate ◽  
Negative Temperature ◽  
X Ray Diffraction ◽  
Total Removal ◽  
Solid State Method ◽  
X Ray ◽  
Conventional Solid State Method ◽  
Molar Percent

In this study, room-temperature driven thermocatalyst (Fe/Sr2Bi2O5 powder) with negative temperature coefficient resistor (NTC) characteristics was prepared by conventional solid state method at various temperatures. Fe/Sr2Bi2O5 powder was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy EDS. The results indicate that Fe/Sr2Bi2O5 powder was prepared and the Fe has been doped successfully in Sr2Bi2O5. The thermocatalyst powder obtained a particular and stable crystal style, meanwhile, besides, well distributed size and rough surface were also found in regard to the thermocatalyst above. On the other hand, the thermocatalyst reactions show that Fe/Sr2Bi2O5 powder has highest removal rate of degradation under the 0.75% (molar percent) content of Fe at 750 oC. The total removal rate of degradation arrives at 93.8% after 3h at 50 oC. Hence, Fe/Sr2Bi2O5 powder may be a potential thermocatalyst at room-temperature for wastewater treatment in the future.

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