scholarly journals A Composite of (95%) La2CoMnO6+ (5%) Ba0.5Na0.5TiO3 : Study of Structural and Dielectric Properties

2021 ◽  
Vol 2070 (1) ◽  
pp. 012093
Author(s):  
Dharmendra Mewada ◽  
Rajesh Kumar Katare
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Room Temperature ◽  
High Dielectric Constant ◽  
Project Work ◽  
X Ray Diffraction ◽  
X Ray ◽  
Frequency Independent ◽  
Diffraction Peaks ◽  
High Dielectric

Abstract This project work reports synthesis, structural and dielectric nature of composite of the type (95%) La2CoMnO6+ (5%) Ba0.5Na0.5TiO3. The composite was characterized at room temperature for structural and dielectric properties. The structural characterization X-ray diffraction was carried for structural confirmation. The XRD data study convey the sample is dual phase in nature evident from the corresponding diffraction peaks. Monoclinic phase was acquired by La2CoMnO6 and the space groupof the phase is P 1 21/n whereas Ba0.5Na0.5TiO3 phase has acquired cubic structure with space group Pm-3m. The frequency dependent dielectric constant examined reveals high dielectric constant which decreases with increase in applied ac field values. Dielectric loss calculated shows the behaviour like dielectric constant which initially decreases abruptly with applied field and later attains frequency independent values. However, the ac conductivity was observed higher in the as synthesized.

Effect of Platinum Substitution on the Microstructures and Dielectric Relaxation of CaCu3Ti4O12 Ceramics

2013 ◽  
Vol 802 ◽  
pp. 134-138 ◽  
Author(s):  
Worawut Makcharoen
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Loss Tangent ◽  
Room Temperature ◽  
High Dielectric Constant ◽  
Ferroelectric Materials ◽  
X Ray Diffraction ◽  
High Loss ◽  
Internal Barrier Layer Capacitor ◽  
High Dielectric

The CaCu3Ti4O12(CCTO) has the advantage for the various applications especially for capacitive elements in microelectronic devices over the ferroelectric materials including BaTiO3. CCTO is a ceramic compound with a high dielectric constant but it has a high loss tangent at room temperature. In this work, the Influences of PtO2doping on the dielectric properties of CaCu3Ti4O12(CCTO) ceramics were investigate. The ceramics CCTO and PtO2doping CCTO were studied by X- ray diffraction, scanning electron microscopy. The dielectric properties have been measured as a function of temperature and frequency range 0.1 - 500 kHz. The XRD shows the CCTO structure does not changes after doping with platinum. The results show that PtO2doped can reduce the mean grain sizes of CCTO, but the dielectric constant still remained a height. The samples of 2.0 mol% Pt-doped have exhibited high dielectric constant of about 22,000 and the loss tangent about 0.7 at room temperature and frequency at 10 kHz. The reduced of the loss tangent could be interpreted with the internal barrier layer capacitor model (IBLC)

scholarly journals Effect of Transition Metal on Structural and Dielectric Properties of Mg0.5Tm0.5Fe2O4 (Tm = Zn and Cu) System

2021 ◽  
Author(s):  
Pallavi Saxena ◽  
Anand Yadav
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Interfacial Polarization ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
High Frequencies ◽  
X Ray ◽  
Cubic Structure ◽  
High Dielectric

This study explored the structural and dielectric features of Mg0.5Tm0.5Fe2O4 (Tm = Zn and Cu) that were synthesized by the Solid-state reaction (SSR) method. The X-ray powder diffraction (XRD) analysis reveals that the prepared samples are single-phase cubic structure without any impurity. Rietveld-refined X-ray diffraction results reveal the formation of cubic structure and all the peaks of Mg0.5Zn0.5Fe2O4 and Mg0.5Cu0.5Fe2O4 are perfectly indexed in the cubic (Fd-3 m) structure. Dielectric constant and dielectric loss variation with frequency were also explored. Both decrease when the relevant alternating field is increasing and become constant at high frequencies which reflects the important role of interfacial polarization. Furthermore, the Mg0.5Cu0.5Fe2O4 having the smallest crystallite size (~ 44.73 nm) has a high dielectric constant (~ 4.41 × 104) value as compare to Mg0.5Zn0.5Fe2O4.

Effect of Sintering Parameters and Ta2O5 Doping on the Microstructure and Dielectric Properties of BaTiO3 Based Ceramics

2014 ◽  
Vol 608 ◽  
pp. 247-252 ◽  
Author(s):  
Md. Fakhrul Islam ◽  
Rubayyat Mahbub ◽  
Adnan Mousharraf
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Room Temperature ◽  
Tantalum Oxide ◽  
X Ray Diffraction ◽  
X Ray ◽  
Xrd Techniques ◽  
Titanate Ceramics ◽  
The Relationship ◽  
Room Temperature Dielectric Constant

The main focus of the research was to correlate the composition and sintering parameters with the microstructure and dielectric properties of Ta2O5 (Tantalum Oxide) doped BaTiO3 (Barium Titanate) ceramics. Ta2O5 was doped at three different percentages viz. 0.5, 1.0 and 1.5 mole%. The doped samples were then sintered using both single and double stage sintering techniques. Thereafter field emission scanning electron microscope (FESEM) and X-ray diffraction (XRD) techniques were used to examine the structure of the samples with particular focus on the incorporation of Ta5+ions into the BaTiO3 crystal lattice. Finally, the dielectric properties were analyzed using impedence analyzer and the relationship between the properties and structure of doped BaTiO3 was established. From the research, it can be stated that double stage sintering yielded best dielectric properties. The best stable value of room temperature dielectric constant (k) of 19000 was obtained for 1.5mole % Ta2O5 doped BaTiO3 sample, sintered at 1320°C for 0 hour and 1280°C for 6 hours due to the combination of high percent theoretical density (%TD) and optimum grain size. At a temperature range of 30°C to 60°C, this combination of composition and sintering parameters yielded dielectric constant in the range of 18000-19000.

Dielectric and Ferroelectric Properties of BaTi1-xSnxO3 Multilayered Ceramics

2007 ◽  
Vol 555 ◽  
pp. 249-254 ◽  
Author(s):  
S. Marković ◽  
M. Mitrić ◽  
Č. Jovalekić ◽  
M. Miljković
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Dielectric Constant ◽  
Transition Temperature ◽  
Room Temperature ◽  
High Dielectric Constant ◽  
Ferroelectric Properties ◽  
X Ray ◽  
High Dielectric ◽  
Scanning Electron

Multilayered BaTi1-xSnxO3 (BTS) ceramics with different Ti/Sn ratios were produced by pressing and sintering at 1420 oC for 2 hours. X-ray diffractometry, scanning electron microscopy and energy dispersive spectroscopy were used for structural, microstructural and elemental analysis, respectively. The dielectric and ferroelectric behavior of sintered samples was studied, too. It is found that in ingredient materials, with increasing Sn content, the tetragonality decreases; Curie temperature moves towards room temperature, while the maximum of the dielectric constant increases, and also, they becomes less hysteretic. It is noticed that multilayered BTS ceramics with different Ti/Sn contents have a broad transition temperature and show a relatively high dielectric constant in a wide temperature range. It is shown that dielectric properties of these materials may be modified by a combination of different BTS powders as well as layers number.

Characterization and Synthesis of Additive Coated BaTiO3 Nano-Powder

2014 ◽  
Vol 881-883 ◽  
pp. 964-967
Author(s):  
Jung Min Lee ◽  
Myoung Pyo Chun ◽  
Hyo Soon Shin ◽  
Byung Ik Kim ◽  
Jong Heun Lee
Keyword(s):  
Dielectric Properties ◽  
High Dielectric Constant ◽  
Coating Layer ◽  
Sintered Sample ◽  
Lattice Parameter ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nano Powder ◽  
Coating Method ◽  
High Dielectric

Two different BaTiO3 (160nm) nanopowders coated with Y and with Dy were fabricated by an aqueous chemical coating method, and their dielectric properties and microstructures were investigated with X-ray diffraction, Impedance analyzer, SEM and TEM. Y and Dy were coated on the BaTiO3 powder using nitrates. Coated BaTiO3 powders were pressed in a disk shape and sintered at 1150~1200°C for 2 hours in reduced atmosphere of 10%H2 - 90%N2. Coating layer of the BaTiO3 particle was thin with a thickness of 3 ~ 5nm. Coated BaTiO3 sintered sample exhibited a larger lattice parameter (a, c) and smaller tetragonality (c/a) than pure BaTiO3 one. Y coated BaTiO3 sample sintered at 1200°C showed good dielectric properties with a high dielectric constant of around 2000 and a stable temperature coefficient of capacitance (TCC).

scholarly journals The influence of the partially europium substitution on the AC electrical properties of BiSr2CaCu2O6.5 ceramics

2019 ◽  
Vol 13 (4) ◽  
pp. 323-332 ◽  
Author(s):  
Zeynep Özdemir ◽  
Mehmet Kılıç ◽  
Yaşar Karabul ◽  
Seda Erdönmez ◽  
Orhan İçelli
Keyword(s):  
Dielectric Constant ◽  
Dielectric Loss ◽  
High Dielectric Constant ◽  
Earth Metal ◽  
Solid State Reaction Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Low Dielectric ◽  
Fourier Transformed Infrared Spectroscopy ◽  
High Dielectric

In this work, EuxBi1-xSr2CaCu2O6.5 (where x = 0, 0.3, 0.5) samples were prepared by solid-state reaction method and sintered at 950?C for 24 h. The structural characterizations were done by X-ray diffraction, X-ray fluorescence, scanning electron microscope and Fourier transformed infrared spectroscopy. The thermal stability of the samples was also analysed by thermogravimetric TG and DTA measurements. It was shown that Eu0.5Bi0.5Sr2CaCu2O6.5 sample exhibited high dielectric constant and low dielectric loss relative to BiSr2CaCu2O6.5 material. Thus, the dielectric loss was lowered by heavy rare earth metal substitution on Bi-Sr-Ca-Cu-O ceramics while the dielectric constant still remained high. Temperature-dependent complex electrical modulus spectra obtained between 296 and 433K also revealed the temperature-activated relaxation process in the materials which can be attributed to the Maxwell-Wagner type polarization effect. Ultimately, it was suggested that the Eu0.5Bi0.5Sr2CaCu2O6.5 ceramics may have a promising potential for applications which require high dielectric constant with a low dielectric loss.

Structural and Dielectric Properties of BaTi1-xSnxO3 Ceramics

2006 ◽  
Vol 518 ◽  
pp. 241-246 ◽  
Author(s):  
S. Marković ◽  
M. Mitrić ◽  
N. Cvjetićanin ◽  
Dragan P. Uskokovic
Keyword(s):  
Dielectric Properties ◽  
Room Temperature ◽  
Dielectric Constants ◽  
X Ray Diffraction ◽  
Solid State Reaction Technique ◽  
X Ray ◽  
Low Dielectric ◽  
High Dielectric ◽  
Tin Content

BaTi1-xSnxO3 (BTS) powders, with x ranging from 0 to 1, were synthesized by solid-state reaction technique. The powders were pressed into pellets and sintered at 1370 and 1420 oC. The structural characterization of sintered BTS samples was made at room temperature using X-ray diffraction and Raman spectroscopy measurements. The BTS samples were found to be singlephase solid solutions. Dielectric properties of sintered BTS samples were studied as a function of sintering temperatures and tin contents, too. For samples with x ranging from 0 up to 0.15, it has been found that the Curie temperature decreases while the maximum of the dielectric constant increases with increasing tin content. These samples have relatively high dielectric constants, contrary to x > 0.2 samples with very low dielectric constants. It is noticed that BTS ceramics sintered at 1420 oC exhibit better dielectric properties than those sintered at 1370 oC.

Atomistic prediction on the configuration- and temperature-dependent dielectric constant of Be0.25Mg0.75O superlattice as a high-κ dielectric layer

2021 ◽  
Author(s):  
Gyuseung Han ◽  
In Won Yeu ◽  
Kun Hee Ye ◽  
Seung-Cheol Lee ◽  
Cheol Seong Hwang ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Dft Calculations ◽  
Bond Length ◽  
Dielectric Layer ◽  
Room Temperature ◽  
High Dielectric Constant ◽  
Temperature Dependent ◽  
High Dielectric

Through DFT calculations, a Be0.25Mg0.75O superlattice having long apical Be–O bond length is proposed to have a high bandgap (>7.3 eV) and high dielectric constant (∼18) at room temperature and above.

Phase Development and Dielectric Properties of 0.98BaTiO3-0.02Ba (Mg1/3Nb2/3) O3 Ceramic

2011 ◽  
Vol 700 ◽  
pp. 58-62
Author(s):  
Rachanusorn Roongtao ◽  
Supagorn Rugmai ◽  
Wanwilai C. Vittayakorn
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Dielectric Constant ◽  
Dielectric Properties ◽  
Loss Factor ◽  
X Ray Diffraction ◽  
Phase Purity ◽  
X Ray ◽  
Phase Development ◽  
Scanning Electron

The 0.98BaTiO3-0.02Ba (Mg1/3Nb2/3) O3ceramics has been synthesized through a conventional mixed-oxide by using BT nanopowder and BMN micropowder. The phase purity of the powders and the ceramics was examined using X-ray diffraction (XRD). The 0.98BT-0.02BMN powders were sintered to 92% of the theoretical density at a temperature of 1300 °C for 2 h. The microstructure of the sintered surface was investigated using scanning electron microscopy (SEM). The dielectric constant (εr) and loss factor (tanδ) of the sintered pellets at Curie temperture were 3000 and 0.015, respectively.

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