scholarly journals Phase, microstructure and microwave dielectric properties of Mg0:95Ni0:05Ti0:98Zr0:02O3 ceramics

2015 ◽  
Vol 33 (1) ◽  
pp. 95-99 ◽  
Author(s):  
Abdul Manan ◽  
Dil Nawaz Khan ◽  
Atta Ullah ◽  
Arbab Safeer Ahmad
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Dielectric Properties ◽  
Microwave Dielectric Properties ◽  
Secondary Phase ◽  
Network Analyzer ◽  
X Ray Diffraction ◽  
X Ray ◽  
Microwave Dielectric ◽  
Scanning Electron

AbstractMg0:95Ni0:05Ti0:98Zr0:02O3 ceramics was prepared via conventional solid-state mixed-oxide route. The phase, microstructure and microwave dielectric properties of the sintered samples were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM) and a vector network analyzer. The microstructure comprised of circular and elongated plate-like grains. The semi quantitative analysis (EDS) of the circular and elongated grains revealed the existence of Mg0:95Ni0:05T2O5 as a secondary phase along with the parent Mg0:95Ni0:05Ti0:98Zr0:02O3 phase, which was consistent with the XRD findings. In the present study, εr ~17.1, Qufo~195855 ± 2550 GHz and τf ~ -46 ppm/K was achieved for the synthesized Mg0:95Ni0:05Ti0:98Zr0:02O3 ceramics sintered at 1325 °C for 4 h.

Microstructure and Microwave Dielectric Properties of Ba5(Nb1-xTax)4O15 (x = 0 ~ 0.5) Ceramics

2007 ◽  
Vol 280-283 ◽  
pp. 9-12 ◽  
Author(s):  
Fei Zhao ◽  
Zhen Xing Yue ◽  
Ying Chun Zhang ◽  
Zhi Lun Gui ◽  
Long Tu Li
Keyword(s):  
Electron Microscopy ◽  
Dielectric Properties ◽  
Large Range ◽  
Sintering Temperature ◽  
Microwave Dielectric Properties ◽  
Relative Content ◽  
X Ray Diffraction ◽  
X Ray ◽  
Microwave Dielectric ◽  
Scanning Electron

The Ba5(Nb1-xTax)4O15 (x=0~0.5) solid-solution ceramics with hexagonal perovskite structure were prepared by solid-state oxide route. The phases and structure of the sintered ceramics were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The influences of composition and sintering temperature on the bulk density, microstructure and microwave dielectric properties were also investigated. As the value of x increased from 0 to 0.5, the Q×f value increases from 36,049 to 49,493 GHz (at ~9GHz), whereas the dielectric constant (εr) decreases from 39.21 to 33.03 and the temperature coefficient of resonant frequency (τf ) decreases from 78.6 to 19.4 ppm/oC. The results indicate that the microwave dielectric properties of Ba5(Nb1-xTax)4O15 ceramics can be easily modified in a large range by changing the relative content of Ta to Nb.

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.

Ordering and microwave dielectric properties of Ba(Ni1/3Nb2/3)O3 ceramics

1997 ◽  
Vol 12 (2) ◽  
pp. 518-525 ◽  
Author(s):  
In-Tae Kim ◽  
Yoon-Ho Kim ◽  
Su Jin Chung
Keyword(s):  
Dielectric Properties ◽  
Microwave Dielectric Properties ◽  
Nucleation And Growth ◽  
Annealing Process ◽  
Network Analyzer ◽  
X Ray Diffraction ◽  
X Ray ◽  
Microwave Dielectric ◽  
Transmission Electron ◽  
Rich Liquid

Ordering and microwave dielectric properties of Ba(Ni1/3Nb2/3)O3 have been investigated using x-ray diffraction, transmission electron microscopy, energy-dispersive spectroscopy, and a network analyzer. Samples sintered at 1400 °C for 2 h were disordered and showed the presence of Nb-rich liquid phase at grain boundary junctions. Degree of ordering increased with following annealing at 1300 °C. Growth of the ordered region during the annealing process was discussed in terms of nucleation and growth. A long-range order parameter was calculated using structure factor. Measurements of microwave dielectric properties showed that permittivity and temperature coefficient of resonant frequency decreased with ordering, and quality factor increased with ordering. The correlation between microwave dielectric properties and ordering was discussed in terms of covalency of bonding, inhomogeneous charge distribution, and defects concentration.

The Electromagnetic Properties of Different Urchinlike Ni Nanostructures

2012 ◽  
Vol 722 ◽  
pp. 47-51
Author(s):  
Hai Ping Qi ◽  
Jun Xi Wan ◽  
Hai Lin Cao ◽  
Yu Dong Huang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Vector Network Analyzer ◽  
Electromagnetic Properties ◽  
Network Analyzer ◽  
X Ray Diffraction ◽  
Electromagnetic Parameters ◽  
X Ray ◽  
Scanning Electron

Urchinlike Ni particles with different spines were synthesized. The microstructures and morphologies of the resulting materials were investigated by X-ray diffraction and scanning electron microscopy. And the electromagnetic parameters of these urchinlike Ni were measured with vector network analyzer at 2-18 GHz frequency. The results indicate that the electromagnetic parameters are affected by morphologies of materials. The long urchin spines will lead to larger permittivity.

STUDY OF HYDROTHERMAL SYNTHESIS AND PROPERTIES OF Bi2Fe4O9

2010 ◽  
Vol 03 (03) ◽  
pp. 173-176 ◽  
Author(s):  
YIBO WANG ◽  
HUAJUN SUN ◽  
JING ZHOU ◽  
BO LI ◽  
CHENGYONG ZHANG ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Phase Transformation ◽  
Dielectric Properties ◽  
X Ray Diffraction ◽  
Impedance Analyzer ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

Highly oriented Bi2Fe4O9 nanosheets can be fabricated with Fe(NO3)3 ⋅ 9H2O and Bi(NO3)3 ⋅ 5H2O using the low-temperature hydrothermal method. The as-prepared powders are characterized with X-ray diffraction (XRD), scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM), which exhibit an excellent orientation along the (00l) planes. The leakage current density and dielectric properties of the nanosheet samples are measured by Radiant Precision Workstation and HP4291B Impedance Analyzer, respectively. The effects of NaOH concentration on the phase transformation, sheet size and morphologies of the Bi2Fe4O9 crystallites are studied in this paper.

Structure and Properties of Bi0.5Na0.5TiO3-BaTiO3 Compound Ceramics

2011 ◽  
Vol 411 ◽  
pp. 503-507
Author(s):  
Xiao Juan Li ◽  
Zeng Zhe Xi ◽  
Wei Long ◽  
Zhi Gang Zhang ◽  
Jia Zhang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Dielectric Properties ◽  
Diffraction Analysis ◽  
Structure And Properties ◽  
X Ray Diffraction ◽  
Oriented Growth ◽  
X Ray ◽  
Scanning Electron

The Bi0.5Na0.5TiO3-xwt%BaTiO3 compound ceramics were prepared. The influence of different BaTiO3 content on structure was evaluated by scanning electron microscopy and X-ray diffraction analysis. The results show oriented is induced by plate-like BaTiO3 template. Signficant improvement of the piezoelectric (d33 = 112 pC/N) and dielectric properties ( max ≈ 5500) was observed. The improvement was attested to the apparent alignment of the BaTiO3 templates and grain oriented growth.

Microstructural and Dielectrical Properties for Ceramics and Thin Films of the xPbTiO3-(1−x)SrTiO3 Solid Solution

2001 ◽  
Vol 688 ◽  
Author(s):  
E. Martínez ◽  
A. Fundora ◽  
O. Blanco ◽  
S. García ◽  
E. Heredia ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Solid Solution ◽  
Scanning Electron Microscopy ◽  
Dielectric Properties ◽  
Integrated Circuit ◽  
X Ray Diffraction ◽  
X Ray ◽  
Analysis Technique ◽  
Dielectrical Properties ◽  
Scanning Electron

AbstractSrTiO3 and PbTiO3 perovskites are combined to form the xPbTiO3-(1−x)SrTiO3 (PST) solid solution. The effect of the PbTiO3 content on the microstructural and dielectric properties is studied for different compositions (x=0.1,0.3,0.5,0.7, and 0.9). Microstructural features of the PST system are studied by X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) techniques. Electrical properties are studied by the thermoelectric analysis technique at both fixed frequency and varying frequency to study the behavior of the dielectric constant and dielectric loss.Films of 0.5PbTiO3-0.5SrTiO3 (PST50) have been obtained by RF ion sputtering on different substrates. We investigate the relation between the crystalline structure and the dielectric properties of PST50 films deposited on different metallic films. Scanning Electron Microscopy (SEM) and X-Ray Diffraction were used for the structural analysis of the PST50/TiN/Si and PST50/RuO2/TiN /Si systems. The dielectric properties of the PST50 films were measured for TiN/PST50/TiN/Si, and RuO2/PST50/RuO2/TiN/Si capacitors and the results were correlated to the structure and composition. The charge storage capabilities of the PST50 films are evaluated for possible application in integrated circuit technology.

Preparation and Electromagnetic Properties of Urchinlike Ni

2013 ◽  
Vol 803 ◽  
pp. 218-221
Author(s):  
Hai Ping Qi ◽  
Hai Lin Cao ◽  
Yu Dong Huang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Vector Network Analyzer ◽  
Electromagnetic Properties ◽  
Network Analyzer ◽  
X Ray Diffraction ◽  
Electromagnetic Parameters ◽  
X Ray ◽  
Microwave Absorbing Properties ◽  
Scanning Electron

Urchinlike Ni particles with different length and quantity spines were successful synthesized. The microstructures and morphologies of the resulting materials were investigated by X-ray diffraction and scanning electron microscopy. The amount of N2H4H2O plays an important role in the morphology of urchin. The electromagnetic parameters of these urchinlike Ni were measured with vector network analyzer at 2-18 GHz frequency. The results indicate that the microwave absorbing properties are improved by the urchin structure.

Sinterability and Microwave Dielectric Properties of Li2CO3-V2O5 Added Mg4Nb2O9-CaTiO3 Composite Ceramics

2010 ◽  
Vol 663-665 ◽  
pp. 1196-1199
Author(s):  
Cui Jin Pei ◽  
Guo Guang Yao ◽  
Hong Ma ◽  
Xiu Lao Tian
Keyword(s):  
Dielectric Properties ◽  
Sintering Temperature ◽  
Microwave Dielectric Properties ◽  
Composite Ceramics ◽  
X Ray Diffraction ◽  
X Ray ◽  
Microwave Dielectric ◽  
Microscopy Techniques ◽  
Co Doped ◽  
Scanning Electron

The effects of Li2CO3-V2O5 (LV) co-doped on the sinterability, phase compositions and microwave dielectric properties of Mg4Nb2O9-CaTiO3 composite ceramics have been investigated. The phase compositions and microstructure were analyzed using X-ray diffraction, energy dispersive X-ray analysis and scanning electron microscopy techniques. The densification sintering temperature is lowed from 1275oC to 1200oC with an amount LV addition. For the specimen with 1.5 wt% LV addition sintered at 1200oC for 5 h exhibited dielectric properties: εr=23, Q·f=24 000 GHz (at 7.7GHz ), τf =1.0 ppm/oC. These properties were correlated with the formation of non-stoichiometric compound Mg4(Nb1-xTix)2O9-δ.

Effects of B2O3 Contents on Crystallization Behaviors and Dielectric Properties of CaO-B2O3-SiO2 Glass Ceramics

2016 ◽  
Vol 680 ◽  
pp. 301-305 ◽  
Author(s):  
Ai Qing Jia ◽  
Wei Jun Zhang ◽  
Xing Yu Cheng ◽  
Zhuo Feng Liu
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Dielectric Properties ◽  
Boron Content ◽  
Glass Ceramics ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Crystalline Phases ◽  
X Ray ◽  
Scanning Electron

The CaO-B2O3-SiO2 glass ceramics system with four different boron contents (14 wt. %, 16.4 wt. %, 18.6 wt. %, 21 wt. %) were prepared under 900oC. The properties and microstructures are characterized by Differential Scanning Calorimeter (DSC), X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). The effects of boron contents on the composition of crystalline phases and the properties of CaO-B2O3-SiO2 glass ceramics system were studied. The results show that when the molar ratio of CaO/SiO2 is 1.06, as the content of B2O3 increases, the major crystalline phases experiences the transformation from CaSiO3 to CaB2O4 and the content of α-SiO2 crystalline phase decreases, and the dielectric constant increases firstly but it decreases after the content of B2O3 reaches to 18.6 wt. %, while the dielectric loss tgδ of decreases gradually with the addition of boron content. When the content of B2O3 is 16.4 wt. %, the CaO-B2O3-SiO2 glass ceramics with a bulk density of 2.47 g/cm3 exhibits good dielectric properties (1 MHz): εr=6.03, tgδ=3.49×10-3.

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