Enhanced Dielectric Properties of Sintered MgFe1.98Nd0.02O4 Nanoparticles

2020 ◽  
Vol 42 (1) ◽  
pp. 87-87
Author(s):  
U Rafiq U Rafiq ◽  
M Hanif M Hanif ◽  
M Anis ur Rehman and A Ul Haq M Anis ur Rehman and A Ul Haq

Spinal MgFe1.98Nd0.02O4 was prepared by simplified sol-gel method. To measure the dielectric properties samples were sintered from 700-800 oC in the steps of 50 oC. The sample’s phase purity, crystallographic phase and crystallite size was measured by X-ray diffraction method (XRD). The pellets were analyzed in Scanning Electron Microscope for their surface morphology and grain shape. Dielectric properties were measured from 20 Hz to 3 MHz at room temperature. Samples sintered at 750 oC, showed highest value of AC conductivity which indicated that the material is suitable for use in sensors. However, minimum value of dielectric loss factor was obtained at 800 and#176;C which makes it more suitable for antenna applications.

2011 ◽  
Vol 700 ◽  
pp. 58-62
Author(s):  
Rachanusorn Roongtao ◽  
Supagorn Rugmai ◽  
Wanwilai C. Vittayakorn

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.


2016 ◽  
Vol 859 ◽  
pp. 18-23 ◽  
Author(s):  
Li Ping Zhao ◽  
Wen Hong Tao ◽  
Xing Hua Fu ◽  
Wen Zhe Cao ◽  
Guo Yuan Cheng ◽  
...  

(Ba0.5Sr0.5)1-xMnxTiO3(x=0,0.01,0.03,0.05)ceramics were prepared via a new sol-gel method with titannium oxide, strontium nitrate, barium nitrate and manganous nitrate as raw materials.The effect of Mn doping on the microstructure and dielectric properties of the BST were characterized by field scanning electron microscopy,x-ray diffraction and impedance analyser.It was found that the dopted ions could not alter the basic crystal strcuture and they only improved the material properties as modified ions when x≤0.3.The (Ba0.5Sr0.5)1-xMnxTiO3 ceramics sintered at 1250°C for 2h exhibited good dielectric properties(er=1330,tand=0.03)at room temperature and f=1KHz when x=0.03 and the grains were regular and uniform ,indicating a dense microstrcture.


2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Ethar Y. Salih ◽  
Zulkifly Abbas ◽  
Samer Hasan Hussein Al Ali ◽  
Mohd Zobir Hussein

Recently, researchers have shown great interest in improving the thermal, mechanical, dielectric, and microwave properties of pure polymers through the use of polymer-based composites. The essential properties of polymer-based composites can be modified by varying the amount of Zn/Al-NO3layered double hydroxide (LDH) added to polyvinyl chloride (PVC). Therefore, by determining the optimal ratio of LDH in the PVC matrix, the dielectric properties of PVC-LDH composites can be improved. An LDH was prepared using the coprecipitation method, while PVC-LDH composites were prepared using tetrahydrofuran (THF) as the solvent. The composites were characterised using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM), and room temperature dielectric measurements were investigated using an RF Impedance/Material Analyzer (Agilent 4291). The results confirmed that the prepared composites were pure. Additionally, the presence of LDH in the PVC matrix was verified. The dielectric measurements showed that an increase in the LDH concentration leads to an increase in the dielectric constant and the dielectric loss factor. When used as dielectric filler in the PVC matrix, the LDH improved the dielectric properties of the fabricated composites. The results indicate that these composites show great potential for use as microwave absorbers at low microwave frequencies.


2012 ◽  
Vol 1494 ◽  
pp. 253-258
Author(s):  
Dan Jiang ◽  
Songwei Han ◽  
Xuelian Zhao ◽  
Jinrong Cheng

ABSTRACTBa0.6Sr0.4TiO3 (BST) thin films were deposited on La0.5Sr0.5CoO3 (LSCO) buffered Ti substrates. Both BST and LSCO were prepared by sol-gel method. X-ray diffraction (XRD) and scanning electron microscopy (SEM) analysis were used to investigate the effect of LSCO sol concentration on the crystallinity and surface morphology of the films. The results show that with the increase of LSCO sol concentration, BST films show variation of the structure and dielectric properties. BST films for LSCO of 0.2 mol/L exhibit a better crystallinity and improved dielectric properties, with the tunability, dielectric constant and tanδ of 30%, 420 and 0.028 respectively.


2021 ◽  
pp. 2150371
Author(s):  
R. F. Rzayev

In this work, the crystal and surface structures of Y2O3 nanoparticles were explored. The exploration of crystal structure was carried out by X-ray diffraction method at room temperature and under normal conditions. It was found that the crystal structure of the Y2O3 compound has a cubic symmetry with an Ia-3 space group. The lattice parameters have the values: [Formula: see text] Å. The surface structure was studied at room temperature and under normal conditions on Scanning Electron Microscope (SEM) microscope. It was found that the nanoparticles of the Y2O3 compound being in the range 20–40 nm are of [Formula: see text] nm size.


2011 ◽  
Vol 471-472 ◽  
pp. 274-278 ◽  
Author(s):  
N.A. Dzulkurnain ◽  
Mohamed Nor Sabirin

(100-x) LiCF3SO3 + (x) CeO2 composite electrolytes were prepared using sol-gel technique followed by sintering at 300 °C for four hours. Structural property and conductivity of the prepared composite electrolytes were studied using X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Energy Dispersive X-Ray (EDX) analysis and Impedance Spectroscopy. The XRD spectra show only crystalline peaks of CeO2 indicating that LiCF3SO3 exists in the form of amorphous phase. This is confirmed by SEM and EDX analyses. The highest ionic conductivity at room temperature is found to be in the order of 10-3 S cm-1 for the composite of 70 mol % LiCF3SO3 - 30 mol % CeO2. The conductivity of the composite electrolytes is observed to increase gradually with temperature.


2020 ◽  
Vol 20 (6) ◽  
pp. 1374
Author(s):  
Azizia Alifi ◽  
Rian Kurniawan ◽  
Akhmad Syoufian

The preparation and characterization of zirconia-supported titania with a zinc dopant had been studied. Zinc-doped titania was grown on the surface of zirconia by the sol-gel method. Various zinc contents and calcination temperatures were applied to investigate the zinc doping effect and crystal structure of the zirconia-titania composite. X-ray diffraction method, Fourier-transform infrared spectroscopy, and UV-Vis reflectance spectroscopy were performed to characterize the composite. The morphology of the composite was observed by using a scanning electron microscope, and its composition was analyzed by using energy dispersive spectroscopy. Among various zinc dopant contents and calcination temperatures investigated, doping with 5% zinc (Zn wt./Ti wt.) at 900 °C calcination shows the best result in response to visible light with a bandgap of 2.87 eV and absorption edge wavelength of 432.61 nm.


2013 ◽  
Vol 423-426 ◽  
pp. 890-893
Author(s):  
Xiao Yan Zhang ◽  
Xi Wei Qi ◽  
Jun Fang Wei ◽  
Wen Shu Hu ◽  
Gui Fang Sun ◽  
...  

A series of (Bi1-xLax)2Al4O9(x = 0, 0.05, 0.10, 0.15, 0.20, 0.25, 0.30, 0.40) ceramics were prepared by sol-gel method with sintering process. Doping dependent investigations were carried out to show the influence of La atom on the structural stability. The products were characterized using X-ray diffraction, scanning electron microscopy. This showed that the second phase is increased gradually by La doping. When the value of La is 0.4, the main phase tends to become LaAlO3. Details on dielectric properties are reported. The permittivity of as-prepared doped samples increases slightly compared to pure Bi2Al4O9and excellent frequency stability is exhibited.


2012 ◽  
Vol 528 ◽  
pp. 121-125 ◽  
Author(s):  
Chao Qun Ye ◽  
Li Ding

The CaCu3Ti4O12 and Zr-doped polycrystalline CaCu3Zr0.05Ti3.95O12 were prepared via sol-gel method. Comprehensive characterization including X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM) equipped with Energy-dispersive X-ray spectroscopy (EDX) were employed to characterize the microstructure, morphology and composition. The dielectric properties of the CCTO based ceramics were studied using impedance analyzer. The results show that replacement of Zr in the Ti- site can achieve the effect of regulation of the dielectric properties.


2016 ◽  
Vol 859 ◽  
pp. 13-17
Author(s):  
Li Ping Zhao ◽  
Wen Hong Tao ◽  
Xing Hua Fu ◽  
Wen Zhe Cao ◽  
Guo Yuan Cheng ◽  
...  

Ba0.5Sr0.5TiO3 powders were prepared via a new sol-gel method with titanium oxide, strontium nitrate, and barium nitrate as raw materials. The microstructure and electrical properties were characterized by field scanning electron microscopy, x-ray diffraction and impedance analyser. When the PH = 4, n (CA): n (metal oins) = 3:1 and the synthesis temperature is 800 °C, Ba0.5Sr0.5TiO3 powders were obtained with good crystallinity. BST ceramics sintered at 1250 °C for 2h exhibited good dielectric properties (εr = 930, tanδ = 0.08) at room temperature and f =1 KHz. The relatively low sintering temperature and excellent dielectric properties would make these ceramics promising for applications in electronics.


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