scholarly journals Structural, Electrical, and Magnetic Study of SrNi2+(Li1+Fe3+)0.5Fe16O27 Ferrite

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
P. R. Arjunwadkar ◽  
M. Y. Salunkhe ◽  
C. M. Dudhe
Keyword(s):  
Solid State Reaction Method ◽  
Product Formation ◽  
Continuous Heating ◽  
High Resistivity ◽  
Conventional Solid State Reaction ◽  
Prolonged Heating ◽  
Mixed Valency ◽  
Site Preferences ◽  
Ferrite Structure ◽  
Ir Bands

W-type ferrite having chemical formula SrNi(LiFe)0.5Fe16O27 was prepared by using conventional solid state reaction method at little low temperature (1100°C). The prolonged and continuous heating resulted in better product formation and it has validated that the Lithium present in the compound facilitates the synthesis. Typical IR bands observed are assigned to the Fe–O bonds in S block of W ferrite structure and the band near 914.3 cm−1 is assigned to the stretching vibrations of Sr–O. High resistivity is found which suggested presence of very small amount of mixed valency cations on equivalent lattice apart from the little amount created due to the release of an electron by divalent Ni to become trivalent. The magnetic properties of compound do not differ much from those of the reported for SrNi2W ferrite except a little decrease in saturation magnetization at room temperature due to canting effect. The experimental observations support presumed site preferences to a greater extent and also the prediction that the Li present on 4fVI sub-lattice results in small canting effect of 12k cations. The low value of coercivity observed is attributed to the larger particle size resulting due to prolonged heating.

Electrical Properties of Nb-Doped and Nb-Mn-Codoped BaTiO3-(Bi0.5Na0.5)TiO3 Lead-Free PTCR Ceramics

2010 ◽  
Vol 67 ◽  
pp. 134-142
Author(s):  
Guo Rong Li ◽  
Sen Lin Leng ◽  
Liao Ying Zheng ◽  
Jiang Tao Zeng ◽  
Zhi Jun Xu ◽  
...  
Keyword(s):  
Room Temperature ◽  
Solid State Reaction Method ◽  
Positive Temperature Coefficient ◽  
Lead Free ◽  
High Resistivity ◽  
Room Temperature Resistivity ◽  
Positive Temperature ◽  
Conventional Solid State Reaction ◽  
Xrd Patterns ◽  
Temperature Resistivity

Nb-doped and Nb-Mn-codoped (1-xmol%)BaTiO3-xmol%(Bi0.5Na0.5)TiO3 (BBNTx) lead-free positive temperature coefficient of resistivity (PTCR) ceramics were prepared by the conventional solid state reaction method. The XRD patterns indicated that all BBNTx samples formed a single perovskite structure with tetragonal phase. 0.25 mol% Nb doped BBNT1 ceramic, sintered at 1330°C for 1h in air, had low room-temperature resistivity (ρ25) of 80 Ω•cm and a high resistivity jump (maximum resistivity [ρmax]/minimum resistivity [ρmin]) of 4.2 orders of magnitude with Tc about 152°C. The Nb-doped BBNTx (10≤x≤60) ceramics also showed distinct PTC effect with Tc between 185 and 232°C by sintering in N2, which was shut off when samples were cooled to a low temperature. In addition, The Nb-Mn-codoped BBNT1 ceramics exhibited higher resistivity jump than the single Nb-doped ones, with increasing the room-temperature resistivity.

Study on Dielectric and Ferroelectric Properties of Gd-Doped Sr2Bi4Ti5O18 Ceramics

2011 ◽  
Vol 328-330 ◽  
pp. 1131-1134
Author(s):  
Qian Chen ◽  
Zhi Jun Xu ◽  
Rui Qing Chu ◽  
Yong Liu ◽  
Ming Li Chen ◽  
...  
Keyword(s):  
Piezoelectric Properties ◽  
Ferroelectric Properties ◽  
Solid State Reaction Method ◽  
Lead Free ◽  
Structural Ceramics ◽  
Conventional Solid State Reaction ◽  
Reaction Method ◽  
Maximum Value ◽  
Pure Bismuth ◽  
Ferroelectric And Piezoelectric Properties

Lead-free piezoelectric ceramics Sr2Bi4-xGdxTi5O18 were prepared by conventional solid-state reaction method. Pure bismuth layered structural ceramics with uniform gain size were obtained in all samples. The effect of Gd-doping on the dielectric, ferroelectric and piezoelectric properties of Sr2Bi4Ti5O18 ceramics were also investigated. It was found that that Gd3+ dopant gradually decreased the Curie temperature (Tc) with the lower dielectric loss (tand) of SBTi ceramics. In addition, Gd-doping with appropriate content improved the ferroelectric and piezoelectric properties of the SBTi ceramics. The piezoelectric constant (d33) of the Sr2Bi3.9Gd0.1Ti5O18 ceramic reached the maximum value, which is 22 pC/N. The results showed that the Sr2Bi4-xGdxTi5O18 ceramic was a promising lead-free piezoelectric material.

Effect of Cu-Excess on the Microstructure and Microwave Dielectric Properties of CaCu3Ti4O12 Ceramics

2015 ◽  
Vol 1087 ◽  
pp. 50-54 ◽  
Author(s):  
Mohamad Johari Abu ◽  
Julie Juliewatty Mohamed ◽  
Mohd Fadzil Ain ◽  
Zainal Arifin Ahmad
Keyword(s):  
Dielectric Constant ◽  
Microwave Dielectric Properties ◽  
Secondary Phase ◽  
Solid State Reaction Method ◽  
Lattice Parameter ◽  
Tangent Loss ◽  
Conventional Solid State Reaction ◽  
Microwave Dielectric ◽  
Order Of Magnitude ◽  
Grain Growth Behavior

CaCu(3+x)Ti4O12 (CCTO) ceramics with different Cu-excess (x = 0 – 0.6) were prepared by conventional solid-state reaction method. Characterization of the prepared ceramics with XRD and FESEM showed that lattice parameter and grain size are slightly increased, indicating Cu-excess to have the big impact on the both phase structure and microstructure. The XRD profiles indicated that the secondary phase (CuO or Cu2O) existed at edge/corner of CCTO grain, which promoted inhibited grain growth behavior. The CCTO ceramics exhibited two trends of dielectric constant related to frequency, which showed a flatter curve about ~50 in 1 – 25 GHz regions, and it’s dropped rapidly to ~35 in 25 – 50 GHz region. With Cu-excess, the dielectric constant of the ceramics was increased for an average of a quarter-order of magnitude, while the tangent loss also increased up to triple times than x = 0, for the same frequency range. Despite enormous increase of dielectric constant related to varying Cu-excess, the tangent loss also increased.

The Morphologies and Photoluminescence of Ce3+-Doped 0.5La2O3-2SrO-0.5Al2O3 Phosphors with SrF2

2016 ◽  
Vol 680 ◽  
pp. 228-232
Author(s):  
Xi Guang Gu ◽  
Ren Li Fu ◽  
Ye Tang ◽  
Fang Yang
Keyword(s):  
Solid State ◽  
White Light ◽  
Solid State Reaction ◽  
Emission Intensity ◽  
Solid State Reaction Method ◽  
Conventional Solid State Reaction ◽  
Light Emitting ◽  
Reaction Method ◽  
Reducing Atmosphere ◽  
White Light Emitting Diodes

Ce3+-doped 0.5La2O3-2SrO-0.5Al2O3 (LSA:Ce) phosphors had been successfully synthesized using a conventional solid-state reaction method under reducing atmosphere (H2/N2 =1/5). The phase, morphologies and luminescence properties of the LSA:Ce phosphors were investigated. The emission intensity of LSA:Ce phosphors was improved by the addition of SrF2 as flux, and red shift of PL spectra peak was observed in this phosphors. Research results shown that the LSA:Ce phosphors have the potential to meet the development of white light-emitting diodes.

A high temperature stable piezoelectric strain of KNN-based ceramics

2018 ◽  
Vol 6 (41) ◽  
pp. 19967-19973 ◽  
Author(s):  
Zhenyong Cen ◽  
Yu Huan ◽  
Wei Feng ◽  
Yan Yu ◽  
Peiyao Zhao ◽  
...  
Keyword(s):  
High Temperature ◽  
Solid State ◽  
Solid State Reaction ◽  
Piezoelectric Ceramics ◽  
Solid State Reaction Method ◽  
Lead Free ◽  
Conventional Solid State Reaction ◽  
Reaction Method ◽  
Piezoelectric Strain

Lead-free (1 − x)(0.96K0.46Na0.54Nb0.98Ta0.02O3–0.04Bi0.5(Na0.82K0.18)0.5ZrO3)–xCaZrO3 ((1 − x)(0.96KNNT–0.04BNKZ)–xCZ) piezoelectric ceramics were prepared by the conventional solid-state reaction method.

Microwave and Electrical Properties of Zr-Doped SrTiO3 for Dielectric Resonator Antenna Application

2018 ◽  
Vol 280 ◽  
pp. 142-148 ◽  
Author(s):  
Norhizatol Fashren Muhamad ◽  
Rozana Aina Maulat Osman ◽  
Mohd Sobri Idris ◽  
Faizal Jamlos ◽  
Nor Azura Malini Ahmad Hambali
Keyword(s):  
Dielectric Constant ◽  
Electrical Properties ◽  
Dielectric Loss ◽  
Dielectric Resonator ◽  
Ceramic Powder ◽  
Experimental Studies ◽  
Orthorhombic Phase ◽  
Solid State Reaction Method ◽  
Dielectric Resonator Antenna ◽  
Conventional Solid State Reaction

Present investigation provides experimental studies on cylindrical dielectric resonator antennas (CDRAs) fabricated from SrTi1-xZrxO3ceramic with different substitution of Zr in place of Ti for (0 ≤ x ≤1). Ceramic powder were prepared using conventional solid state reaction method. X-ray Diffraction exposes physical properties Zr-doped SrTiO3which exhibit phase transition from cubic, tetragonal to orthorhombic phase. The electrical properties such as dielectric constant (εr) and dielectric loss (tan δ) were studied in variation of temperatures and frequencies. At room temperature the dielectric constant decreased from 240 to 21 with increase of Zr content however the amazing result was obtained for multiband antenna by Zr content. The dielectric loss obtain shows very low loss value roughly below 0.07 for all samples. The variations of return loss, resonance frequency and bandwidth of CDRAs at their respective resonant frequencies are studied experimentally.

The structural, magnetic and electrical transport properties of perovskite La0.67Sr0.33Mn1−x(VMn)xO3: The B-sites vacancies as a rapier

2021 ◽  
pp. 2150415
Author(s):  
Denghui Ji ◽  
Bin Zhang ◽  
Yong Yang ◽  
Shuling Wang ◽  
Yingdi Liu ◽  
...  
Keyword(s):  
Electrical Transport ◽  
Double Exchange ◽  
Secondary Phase ◽  
Solid State Reaction Method ◽  
Photoelectron Spectra ◽  
Small Range ◽  
Electrical Transport Properties ◽  
Conventional Solid State Reaction ◽  
Double Exchange Interaction ◽  
X Ray

The polycrystalline samples of manganites perovskite [Formula: see text] with B-sites vacancies were synthesized using the conventional solid-state reaction method. The results based on the X-Ray Diffraction (XRD) and Scanning Electron Microscope (SEM) analyses show that the samples with [Formula: see text] have a secondary phase of lanthanum oxides. It indicates there is a maximum vacancy content at the B-sites with [Formula: see text]. By X-ray Photoelectron Spectra (XPS), the ionicities of oxygen were determined to be 0.762, 0.842, and 0.886, corresponding to [Formula: see text], 0.03, and 0.05, respectively. The B-sites vacancy plays an important role in magnetic performances: (i) B-sites vacancy changes the contents and the average cant angle of Mn cations, and makes the specific saturation magnetization at 100 K and 300 K increase, and then decrease rapidly. (ii) The Curie temperature changes in a small range from 363.93 K to 366.00 K, resulting from both the double exchange interaction increasing and the double exchange path destroyed by the vacancies. (iii) The magnetoresistance (MR) at room temperature achieves 6.97% in the [Formula: see text] sample, whose value is larger than that of [Formula: see text] sample.

Structure and Electrical Characteristics of BaTiO3 and Ba0.99Er0.01TiO3 Ceramics

2018 ◽  
Vol 280 ◽  
pp. 127-133 ◽  
Author(s):  
F. A. Ismail ◽  
Rozana Aina Maulat Osman ◽  
Mohd Sobri Idris ◽  
N.A.M. Ahmad Hambali
Keyword(s):  
Perovskite Phase ◽  
Microstructural Analysis ◽  
Xrd Analysis ◽  
Solid State Reaction Method ◽  
X Ray Diffraction ◽  
Conventional Solid State Reaction ◽  
Grain Sizes ◽  
Capacitance Voltage ◽  
Ion Incorporation ◽  
Voltage Breakdown

Conventional solid state reaction method was used to prepare BaTiO3 and Ba0.99Er0.01TiO3 ceramics. Influence of Er3+ ion incorporation on their structural, microstructural and electrical properties was studied. The phase pure samples were obtained when heated at 1400 °C for overnight. The tetragonal perovskite phase of BaTiO3 and Ba0.99Er0.01TiO3 was confirmed by using X-ray Diffraction (XRD) analysis which is in agreement with results obtained from Rietveld refinement analysis. The lattice parameters and unit cell volume of BaTiO3 increased when doped with Erbium. Microstructural analysis of BaTiO3 and Ba0.99Er0.01TiO3 ceramics showed that the grain sizes of BaTiO3 and Ba0.99Er0.01TiO3 significantly decreased. The dielectric properties of BaTiO3 and Ba0.99Er0.01TiO3 were investigated as a function of temperature and frequency. It revealed that the Curie temperature (TC) increased by doping Er content from 110 °C to 120 °C. Ba0.99Er0.01TiO3 exhibited the high value of dielectric constant (ε=5929) at TC of 120 °C. The capacitance-voltage characteristic revealed that the voltage breakdown for both BaTiO3 and Ba0.99Er0.01TiO3 exceeded 30 V.

scholarly journals Effect of Bi2O3 content on the microstructure and electrical properties of SrBi2Nb2O9 piezoelectric ceramics

RSC Advances ◽  
2018 ◽  
Vol 8 (28) ◽  
pp. 15613-15620 ◽  
Author(s):  
Xiaochun He ◽  
Ruiqing Chu ◽  
Zhijun Xu ◽  
Zhongran Yao ◽  
Jigong Hao
Keyword(s):  
Solid State ◽  
Electrical Properties ◽  
Solid State Reaction ◽  
Solid State Reaction Method ◽  
Lead Free ◽  
Molar Ratio ◽  
Conventional Solid State Reaction ◽  
Reaction Method ◽  
Lead Free Ceramics ◽  
Bi2o3 Content

Lead-free ceramics, SrBi2Nb2O9–xBi2O3 (SBN–xBi), with different Bi contents of which the molar ratio, n(Sr) : n(Bi) : n(Nb), is 1 : 2(1 + x/2) : 2 (x = −0.05, 0.0, 0.05, 0.10), were prepared by conventional solid-state reaction method.

Study of Magnetic Transition and Magnetocaloric Effect in La1-xSrxMnO3 (0.20≤ x ≤0.35) Compounds

2013 ◽  
Vol 378 ◽  
pp. 225-229 ◽  
Author(s):  
Yeong Seung Jeong ◽  
M.S. Anwar ◽  
Faheem Ahmed ◽  
Seung Rok Lee ◽  
Bon Heun Koo
Keyword(s):  
Curie Temperature ◽  
Magnetic Entropy Change ◽  
Perovskite Phase ◽  
Magnetic Transition ◽  
Entropy Change ◽  
Solid State Reaction Method ◽  
Magnetic Entropy ◽  
Conventional Solid State Reaction ◽  
Ionic Radii ◽  
The Difference

We report the magnetic transition and large magnetic entropy change in Sr doped lanthanum manganites. Polycrystalline La1-xSrxMnO3(0.20x0.35) samples were prepared using the conventional solid-state reaction method. The results of X-ray diffraction indicates perovskite phase without any impurity. The magnetic study has revealed that the Curie temperature is influenced by Sr-concentration. The doping of Sr at La site affects the Mn-O bond length and Mn-O-Mn bond angle due to the difference in their ionic radii, consequently, the Curie temperature changed. A large magnetic entropy change has been observed for La0.8Sr0.2MnO3sample, the value of the maximum entropy change (SMmax) increases from 1.42 to 2.74 J/kgK as magnetic field increases from 1 to 2.5 T. This investigation suggests that La1-xSrxMnO3can be used as a potential magnetic refrigeration material.

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