Crystallization Behavior of Ferroelectric Glass-Ceramics of the Na2O-Nb2O5-Al2O3-SiO2 System Contained TiO2

2009 ◽  
Vol 421-422 ◽  
pp. 189-192 ◽  
Author(s):  
Anuson Niyompan ◽  
Kanita Srisurat ◽  
Rungnapa Tipakontitikul
Keyword(s):  
Glass Ceramic ◽  
Crystallization Behavior ◽  
Volume Fraction ◽  
Treatment Time ◽  
Glass Ceramics ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ceramic Samples ◽  
Alumino Silicate ◽  
Quenched Glass

The ferroelectric glass-ceramic of the composition Na2O-Nb2O5-Al2O3-SiO2 was prepared by controlling crystallization of the glass that added with small amount of TiO2. The effect of TiO2 content on crystallization behavior and the dielectric property were determined. X-ray diffraction studied indicated that NaNbO3, NaNbO8 and a compound of alkali alumino silicate composition were readily formed in the as-quenched glass as the product of phase separation. After treatment at 700oC for various times, NaNbO3 volume fraction was found to increase with time. Crystalline size of the NaNbO3 was lower than 300 nm and it was developed with treatment time. Presence of TiO2 had considerably effect on NaNbO3 volume fraction when treatment time shorter than 1.0 h. The dielectric response of the glass-ceramic samples was found to arise from all contributions of crystalline phases and glass matrix responds.

scholarly journals Crystallization Behavior and Microstructure of Bio Glass-Ceramic System

2013 ◽  
Vol 19 ◽  
pp. 58-68 ◽  
Author(s):  
Behzad Mehdikhani ◽  
Gholam Hossein Borhani
Keyword(s):  
Glass Ceramic ◽  
Crystallization Behavior ◽  
Glass Ceramics ◽  
Al2o3 Content ◽  
Sintering Behavior ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ceramic Samples ◽  
Molar Percent ◽  
Glass Compositions

The effects of Al2O3 on the crystallization behavior of glass compositions in the Na2O-CaO-SiO2 system were investigated by differential thermal analysis (DTA), X-ray diffraction (XRD) and scanning electron microscopy (SEM). Effect of Al2O3 content on the mechanical, density, phase formation and microstructures of Na2O-CaO–P2O5–Al2O3-SiO2 glass ceramics were studied. Thermal parameters of each glass were studied by DTA. The density of the glass ceramic samples was measured by Archimedes’ method. It was found that the glass–ceramic containing 2.0 molar percent Al2O3 had desirable sintering behavior and reached to an acceptable density. Phase investigation and micro structural study were performed by XRD and SEM, respectively.

MgO-Al2O3-SiO2 Glass-Ceramic Prepared by Sol-Gel Method

2010 ◽  
Vol 92 ◽  
pp. 131-137 ◽  
Author(s):  
Qiu Hua Yuan ◽  
Pei Xin Zhang ◽  
Li Gao ◽  
Hai Lin Peng ◽  
Xiang Zhong Ren ◽  
...  
Keyword(s):  
Glass Ceramic ◽  
Crystallization Behavior ◽  
Glass Powder ◽  
Sol Gel ◽  
Glass Ceramics ◽  
Green Body ◽  
Sintering Process ◽  
X Ray Diffraction ◽  
Sio2 Glass ◽  
X Ray

The crystallization behavior of MgO-Al2O3-SiO2 glass-ceramics by sol-gel technology was investigated by using x-ray diffraction (XRD), differential thermal analysis (DTA), Scanning electron microscopy (SEM). The results showed that: (1)α-cordierite phase was precipitated when the green body was calcined at 1050°C, and α-cordierite of high purity and stability could be formed at 1100°C; (2) Adding an appropriate amount of low melting point glass powder into the green body may provide liquid-phase environment during the sintering process, which will help enhance the tightness density of glass-ceramic, and thus improve its flexural strength.

scholarly journals Crystallization Behavior and Microstructural Analysis of Lead-Rich () Glass Ceramics Containing 1 mole

2011 ◽  
Vol 2011 ◽  
pp. 1-11 ◽  
Author(s):  
C. R. Gautam ◽  
Devendra Kumar ◽  
Om Parkash
Keyword(s):  
Transition Metal Oxides ◽  
Glass Ceramic ◽  
Crystallization Behavior ◽  
Perovskite Phase ◽  
Microstructural Analysis ◽  
Glass Ceramics ◽  
Glassy Matrix ◽  
X Ray Diffraction ◽  
X Ray ◽  
Higher Temperature

Solid solution of perovskite Pb,SrTiO3in Pb-rich composition can be crystallized in borosilicate glassy matrix. The addition of rare earth and transition metal oxides is known to influence the crystallization behavior and surface morphology of perovskite crystallites in glassy matrix. In the present paper, the glasses in the lead-rich system 64[(PbxSr1-x)·TiO3]-25[2SiO2·B2O3]-5[K2O]-5[BaO] () with the addition of 1 mol % La2O3were prepared to study its effect on their crystallization behavior. Differential thermal analysis (DTA) patterns show one or more exothermic crystallization sharp peaks, which shift towards higher temperature with increasing concentration of SrO. The glasses were subjected to various heat-treatment schedules for crystallization. X-ray diffraction analysis of these glass ceramic samples shows that major crystalline phase of the entire glass ceramic sample with was found to have tetragonal structure similar to PbTiO3ceramic, and addition of La2O3enhances the crystallization of the perovskite phase and retards the crystallization of minor phases.

Effect of Gradual Substitution of CaO by SrO in Glass-Ceramic Materials of the System SiO2 - Al2O3 - CaF2 - RO (R = Ca, Mg, Sr)

2012 ◽  
Vol 1373 ◽  
Author(s):  
M. Garza-García ◽  
J. López-Cuevas ◽  
C.A. Gutiérrez-Chavarría ◽  
N. Piedad-Sánchez ◽  
E. Camporredondo-Saucedo ◽  
...  
Keyword(s):  
Glass Ceramic ◽  
Vickers Microhardness ◽  
Glass Ceramics ◽  
Ceramic Materials ◽  
X Ray Diffraction ◽  
X Ray ◽  
Substitution Level ◽  
Glass Ceramic Materials ◽  
Ceramic Samples ◽  
Crystallization Fraction

ABSTRACTThe density, Vickers microhardness and crystallization fraction of glass-ceramic materials synthesized from parent glasses are determined in which CaO is gradually substituted by SrO. The chemical composition (in mol.%) of the parent glasses is 54SiO2-(23-X)CaO-12MgO-5Al2O3-6CaF2-XSrO, where X is the employed CaO substitution level (X = 0, 3, 6 and 9 mol.%, with X = 0 corresponding to the reference material). In order to determine the type of crystallization occurring in the glass-ceramic samples, as well as the crystalline phases formed in them, these are characterized by both Scanning Electron Microscopy (SEM/EDS) and X-Ray Diffraction (XRD). Independently of the CaO substitution level employed, the glass-ceramics show the formation of a solid solution corresponding to diopside-type pyroxene, with chemical formula Ca(Mg,Al)(Al,Si)2O6, as a single crystalline phase. The synthesized glass-ceramic materials with the reference composition show the highest Vickers microhardness and crystallization fraction, as well as the lowest density.

Influence of Boron on Glass-Ceramic Magnetic Performance for Hyperthermia Application

2013 ◽  
Vol 834-836 ◽  
pp. 305-308
Author(s):  
Jian An Liu ◽  
Mei Mei Zhang ◽  
Xue Na Yang
Keyword(s):  
Glass Ceramic ◽  
Crystallization Behavior ◽  
Boron Content ◽  
Magnetic Measurements ◽  
Glass Ceramics ◽  
X Ray Diffraction ◽  
X Ray ◽  
Magnetic Performance ◽  
Co Precipitation

Ferromagnetic glass-ceramics for hyperthermia application were obtained by melting of the co-precipitation-derived precursor from the nominal compositions SiO2-B2O3-Fe2O3-SrO-Na2O. The influence of boron content on magnetic performance of these glasses was investigated. Glass-ceramics were characterized by x-ray diffraction and magnetic measurements. The crystallization behavior of the glasses was investigated.

scholarly journals Bone bonding ability of some borate bio-glasses and their corresponding glass-ceramic derivatives

2012 ◽  
Vol 6 (4) ◽  
pp. 183-192 ◽  
Author(s):  
Fatma Margha ◽  
Amr Abdelghany
Keyword(s):  
Heat Treatment ◽  
Fourier Transform ◽  
Glass Ceramic ◽  
Glass Composition ◽  
Glass Ceramics ◽  
Soda Lime ◽  
Phosphate Solution ◽  
Borate Glasses ◽  
X Ray Diffraction ◽  
X Ray

Ternary borate glasses from the system Na2O?CaO?B2O3 together with soda-lime-borate samples containing 5 wt.% of MgO, Al2O3, SiO2 or P2O5 were prepared. The obtained glasses were converted to their glass-ceramic derivatives by controlled heat treatment. X-ray diffraction was employed to investigate the separated crys?talline phases in glass-ceramics after heat treatment of the glassy samples. The glasses and corresponding glass-ceramics after immersion in water or diluted phosphate solution for extended times were characterized by the grain method (adopted by several authors and recommended by ASTM) and Fourier-transform infrared spectra to justify the formation of hydroxyapatite as an indication of the bone bonding ability. The influence of glass composition on bioactivity potential was discussed too.

Structure Characterization of Sintered CaO-Al2O3-SiO2 Glass-Ceramic Reinforced with Spodumene

2013 ◽  
Vol 834-836 ◽  
pp. 309-314
Author(s):  
Zi Fan Xiao ◽  
Jin Shu Cheng ◽  
Jun Xie
Keyword(s):  
Glass Ceramic ◽  
Energy Dispersive Spectrometry ◽  
Crystal Size ◽  
Bending Strength ◽  
Glass Ceramics ◽  
Structure Characterization ◽  
X Ray Diffraction ◽  
Crystalline Phases ◽  
X Ray

A glass-ceramic belonging to the CaO-Al2O3-SiO2(CAS) system with different composition of spodumene and doping the Li2O with amount between 0~2.5 % (mass fraction) were prepared by onestage heat treatment, under sintering and crystallization temperature at 1120 °C for two hours. In this paper, differential thermal analysis, X-ray diffraction, scanning electron microscopy, energy dispersive spectrometry and bending strength test were employed to investigate the microstructure and properties of all samples. β-wollastonite crystals were identified as the major crystalline phases, and increasing Li2O was found to be benefit for the crystallization and tiny crystalline phases remelting, resulting in the content of major crystalline phases increased first and then decreased with increasing the expense of spodumene. Meanwhile, the crystal size can be positively related with the content of Li2O. The preferable admixed dosage of spodumene can be obtained, besides the strength of glass-ceramics can be more than 90 MPa.

Effects of Different Content of TiO2 on Crystallization Behavior and Properties of Li2O-ZnO-SiO2 Glass-Ceramics

2014 ◽  
Vol 1035 ◽  
pp. 263-267
Author(s):  
Xiu Quan Zhao ◽  
Zheng Cao ◽  
Yu Teng Wu ◽  
Hong Jiang ◽  
Chang Jiu Li ◽  
...  
Keyword(s):  
Crystallization Behavior ◽  
Glass Ceramics ◽  
Ceramic Materials ◽  
Xrd Analysis ◽  
Spherical Particles ◽  
X Ray Diffraction ◽  
X Ray ◽  
Glass Ceramic Materials ◽  
Average Coefficient ◽  
Different Content

Glass-ceramic materials of the Li2O-ZnO-SiO2 system, with various amounts of TiO2 added, have been prepared. The appropriate heat treatment temperatures were selected according to the information provided by the differential thermal analysis (DTA). X-ray diffraction (XRD) analysis demonstrated that in the LZS glass-ceramics system, the main phases are Li2ZnSiO4, cristobalite, tridymite and quartz. The scanning electron microscopy (SEM) revealed that crystals appear as lamellar and spherical particles in the glass-ceramics samples. In addition, the average coefficient of the thermal expansion (CTE) values first decreased, then increased and finally tended to flatten. When the content of TiO2 increased to 6%, the CTE value decreased to 9.15×10-6/K, reached the lowest value. When the content of TiO2 increased to 10%, the CTE value reached highest value 13.90×10-6/K.

Crystallization and Mechanical Properties of Glass-Ceramic from Silicon Slag

2014 ◽  
Vol 953-954 ◽  
pp. 1643-1648
Author(s):  
Hang Li ◽  
Li Qiang Liu ◽  
Min Jing ◽  
Zhi Gang Wang ◽  
Zheng Wang ◽  
...  
Keyword(s):  
Glass Ceramic ◽  
Mechanical Performance ◽  
Glass Ceramics ◽  
Ceramic Materials ◽  
Micro Hardness ◽  
X Ray Diffraction ◽  
Talcum Powder ◽  
X Ray ◽  
Glass Ceramic Materials ◽  
Spherical Grains

The glass-ceramic materials were produced from silicon slag with the addition of talcum powder and TiO2 by melting them in an electrically heated furnace and subsequent heat treatment at various temperatures and time. The microstructure and crystallization behaviors of glass–ceramics have been investigated by differential thermal analysis (DTA), X-ray diffraction (XRD) and scanning electron microscopy (SEM). With the increase of silicon slag content, the sequent precipitate phase is: krinovite Na (Mg1.9Fe0.1)Cr (SiO)3O, pseudobrookite Fe2TiO5 and anorthite Ca (Al2Si2O8), enstatite ferroan MgFeSi2O6, and albite Na (AlSi3O8). The shape of crystals was spherical grains. The glass–ceramic sample obtained from 70% silicon slag had the excellent mechanical performance including flexural strength of 200.45 MPa and Vickers micro hardness of 909.72 MPa.

scholarly journals Investigation on Structural and Optical Properties of Willemite Doped Mn2+Based Glass-Ceramics Prepared by Conventional Solid-State Method

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Nur Farhana Samsudin ◽  
Khamirul Amin Matori ◽  
Josephine Ying Chi Liew ◽  
Yap Wing Fen ◽  
Mohd Hafiz Mohd Zaid ◽  
...  
Keyword(s):  
Glass Ceramic ◽  
Glass Ceramics ◽  
Structural Evolution ◽  
Emission Spectra ◽  
Soda Lime ◽  
X Ray Diffraction ◽  
Glass Waste ◽  
Solid State Method ◽  
Ceramic Samples ◽  
Zno Crystal

Mn-doped willemite (Zn2SiO4:Mn2+) glass-ceramics derived from ZnO-SLS glass system were prepared by a conventional melt-quenching technique followed by a controlled crystallization step employing the heat treatment process. Soda lime silica (SLS) glass waste, ZnO, and MnO were used as sources of silicon, zinc, and manganese, respectively. The obtained glass-ceramic samples were characterized using the X-ray diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM), Fourier Transform Infrared (FTIR), UV-Visible (UV-Vis), and photoluminescence (PL) spectroscopy. The results of XRD revealed that ZnO crystal and willemite (β-Zn2SiO4) were presented as major embedded crystalline phases. This observation was consistent with the result of FESEM which showed the presence of irregularity in shape and size of willemite crystallites. FTIR spectroscopy exhibits the structural evolution of willemite based glass-ceramics. The optical band gap shows a decreasing trend as the Mn-doping content increased. Photoluminescent technique was applied to characterize the role of Mn2+ions when entering the willemite glass-ceramic structure. By measuring the excitation and emission spectra, the main emission peak of the glass-ceramic samples located at a wavelength of 585 nm after subjecting to 260 nm excitations. The following results indicate that the obtained glass-ceramics can be applied as phosphor materials.

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