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

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.

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.


2019 ◽  
Vol 966 ◽  
pp. 200-203
Author(s):  
Zaenal Arifin ◽  
Triwikantoro ◽  
Bintoro Anang Subagyo ◽  
Mochamad Zainuri ◽  
Darminto

Abstract. In this study, the CaCO3 powder has been successfully synthesized by mixing CaCl2 from natural limestone and Na2CO3 in the same molar ratio. The mixing process of solutions was carried out by employing the molar contents of 0.125, 0.25, 0.375 and 0.5M at varying temperatures of 30, 40, 60 and 80ᴼC. The produced CaCO3 microparticles were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The highest content of aragonite phase with morphology rod-like of the samples is around 29 wt%, resulting from the process using solution of 0.125 M at 80 ᴼC. While at 30 ᴼC and 40 ᴼC produced 100 wt% calcite phase.


2015 ◽  
Vol 33 (1) ◽  
pp. 95-99 ◽  
Author(s):  
Abdul Manan ◽  
Dil Nawaz Khan ◽  
Atta Ullah ◽  
Arbab Safeer Ahmad

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.


2009 ◽  
Vol 79-82 ◽  
pp. 1503-1506 ◽  
Author(s):  
Qing Bo Tian ◽  
Li Na Xu ◽  
Li Yang ◽  
Yan Sheng Yin

The influences of Fe2O3 doping on crystallization characteristics and microstructural morphology in the SiO2-Al2O3-MgO-K2O-ZrO2-F glass were investigated by using differential scanning calorimeter, X-ray diffraction and scanning electron microscopy techniques. The results indicate that the addtions of Fe2O3 shift the crystallization peaks to higher temperatures and the crystallization peaks increases in magnitude and the gap values between two crystallization peak temperatures boarden with the increment of Fe2O3 contents.The star-shaped crystals of cordietite by dendritic-manner growths are homogeneously precipitated in the rusidual glass. The mica phases, which are precipitated at interdendritic cordietite phases and formed the plate shapes at the elevated temperatures. The mica crystals grow at the expense of cordietite phases and finally form the composites of mica/cordietite uniformly distributed.


2008 ◽  
Vol 368-372 ◽  
pp. 995-997
Author(s):  
Cui Wei Li ◽  
Hong Xiang Zhai ◽  
Yang Zhou ◽  
Shi Bo Li ◽  
Zhi Li Zhang

In this study, free Ti/Si/Al/C powder mixtures with molar ratio of 3:0.4:0.8:1.8 were heated in Argon with various schedules, in order to reveal the possibility for the synthesis of Ti3Si0.4Al0.8C1.8 solid solution powder. X-ray diffraction (XRD) was used for the evaluation of phase identities of the powder after different treatments. Scanning electron microscopy (SEM) was used to observe the morphology of the Ti3Si0.4Al0.8C1.8 solid solution. XRD results showed that predominantly single phase samples of Ti3Si0.4Al0.8C1.8 was prepared after heating at 1400oC for 5 min in Argon and the lattice parameters of Ti3Si0.4Al0.8C1.8 lay between those of Ti3SiC2 and Ti3AlC2.


2010 ◽  
Vol 03 (03) ◽  
pp. 173-176 ◽  
Author(s):  
YIBO WANG ◽  
HUAJUN SUN ◽  
JING ZHOU ◽  
BO LI ◽  
CHENGYONG ZHANG ◽  
...  

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.


2011 ◽  
Vol 411 ◽  
pp. 503-507
Author(s):  
Xiao Juan Li ◽  
Zeng Zhe Xi ◽  
Wei Long ◽  
Zhi Gang Zhang ◽  
Jia Zhang

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.


2008 ◽  
Vol 368-372 ◽  
pp. 1412-1414 ◽  
Author(s):  
Jin Shu Cheng ◽  
Hui Guang Qiu ◽  
Hong Li ◽  
Jun Xie

CaO-A12O3-SiO2 (CAS) system glass-ceramics were prepared by sintering with certain amount of yellow phosphorus slag. The effects of phosphorus and fluorine on the nucleation, crystallization and structure of CAS system glass-ceramics were investigated by differential thermal analysis, X-ray diffraction, scanning electron microscopy and other measuring methods. Glass-ceramics of CAS system with 42.32wt% yellow phosphorus slag were obtained by nucleating at 615°C for 1 hour and crystallizing at 926°C for 2 hours. The results showed that the introduction of phosphorus and fluorine promoted the nucleation and crystallization of glass-ceramics, lowering the crystallizing temperature. The main crystal phase of glass-ceramics was β-wollastonite. The density of the glass-ceramic was 2.695g/cm3.


2001 ◽  
Vol 688 ◽  
Author(s):  
E. Martínez ◽  
A. Fundora ◽  
O. Blanco ◽  
S. García ◽  
E. Heredia ◽  
...  

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.


2015 ◽  
Vol 34 ◽  
pp. 91-97 ◽  
Author(s):  
Suresh Sagadevan

Cu doped SnO2nanoparticles were prepared using the chemical precipitation method. The Cu doped SnO2nanoparticles have been characterized by powder X-ray diffraction (XRD) analysis, Scanning electron microscopy (SEM), elemental dispersive X-ray (EDX) analysis, Transmission electron microscopy (TEM), UV-Visible absorption spectrum and Dielectric studies. The average crystalline size of Cu doped SnO2nanoparticles was calculated from the X-ray diffraction (XRD) pattern and found to be 15 nm and it was further confirmed from the transmission electron microscopy (TEM) studies. The scanning electron microscopy (SEM) analysis showed that the nanoparticles agglomerate forming spherical-shaped particles. The elemental composition of Cu doped SnO2nanoparticles was analyzed by Energy Dispersive X-ray (EDX) spectrum. The optical absorption study clearly shows that the absorption edge shift towards the higher wavelength region. The dielectric properties of Cu doped SnO2nanoparticles have been studied in the different frequency at different temperatures. The dielectric constant and dielectric loss of the Cu doped SnO2nanoparticles decreases with increase in frequency. Cu doped SnO2nanoparticles were prepared using the chemical precipitation method. The Cu doped SnO2nanoparticles have been characterized by powder X-ray diffraction (XRD) analysis, Scanning electron microscopy (SEM), elemental dispersive X-ray (EDX) analysis, Transmission electron microscopy (TEM), UV-Visible absorption spectrum and Dielectric studies. The average crystalline size of Cu doped SnO2nanoparticles was calculated from the X-ray diffraction (XRD) pattern and found to be 15 nm and it was further confirmed from the transmission electron microscopy (TEM) studies. The scanning electron microscopy (SEM) analysis showed that the nanoparticles agglomerate forming spherical-shaped particles. The elemental composition of Cu doped SnO2nanoparticles was analyzed by Energy Dispersive X-ray (EDX) spectrum. The optical absorption study clearly shows that the absorption edge shift towards the higher wavelength region. The dielectric properties of Cu doped SnO2nanoparticles have been studied in the different frequency at different temperatures. The dielectric constant and dielectric loss of the Cu doped SnO2nanoparticles decreases with increase in frequency.


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