Crystallization Behavior and Optical Properties of Glass-Ceramics Containing Nano-Diopside Crystals

2020 ◽  
Vol 12 (4) ◽  
pp. 510-515
Author(s):  
Byeongguk Kang ◽  
Seunggu Kang
Keyword(s):  
Crystal Growth ◽  
Glass Ceramic ◽  
Crystallization Behavior ◽  
Building Materials ◽  
Red Light ◽  
Glass Ceramics ◽  
Nucleating Agent ◽  
Light Transmittance ◽  
Excitation Light ◽  
Bulk Crystallization

Diopside is a ceramic material with excellent properties including a low dielectric constant, high thermal conductivity, low sintering temperature below 1000 °C, and high mechanical strength. It has been applied to wireless and optical communications, substrates for touch panels, lenses for UV-LED, building materials, and so on. In this study, glass-ceramics containing nano-sized diopside crystals were fabricated, and their transmittance at visible light and photoluminescence were evaluated. In particular, TiO2 was added as a nucleating agent to suppress the surface crystallization phenomenon and Mn was used as a dopant to emit red light. The glass-ceramics were prepared by heat treatment at a temperature lower than the maximum crystal growth temperature (TP) calculated from the non-isothermal analysis method using differential thermal analysis (DTA) for the formation of nano-sized crystals. For glass containing 20 wt% of TiO2, the Avrami constant was calculated to be 2.23 and the activation energy required for crystal growth to be 549 kJ/mol, reflecting typical bulk crystallization behavior. Glass-ceramics with high light transmittance up to 70% were obtained by inducing the bulk crystallization behavior, and the diopside crystal size was less than 10 nm, which was equal to or higher than that of commercialized transparent glass-ceramic products. Glass-ceramic specimens doped with Mn showed luminescence of 736∼766 nm wavelength at excitation light of 365 nm wavelength. The emission peak intensity increased with the amount of dopant added, but gradually decreased with increasing crystallinity of the diopside phase.

Nano-Crystallization Behavior and Optical Properties of Diopside: Eu2O3-Based Glass-Ceramic System

2021 ◽  
Vol 21 (3) ◽  
pp. 1996-2000
Author(s):  
Byeong-Guk Kang ◽  
Seung-Gu Kang
Keyword(s):  
Glass Ceramic ◽  
Crystallization Behavior ◽  
Light Emission ◽  
Red Light ◽  
Nucleating Agent ◽  
Treatment Temperature ◽  
Light Transmittance ◽  
Excitation Light ◽  
Light Emitting ◽  
The Relationship

In this study, glass-ceramic was prepared by adding TiO2 as a nucleating agent to induce the internal crystallization behavior of diopside (CaO-MgO-2SiO2)-based glass. The optimum composition for producing a transparent glass-ceramic was a composition of 15 wt% of TiO2 mixed with 85% diopside. The light transmittance of the specimen decreased as the heat treatment temperature increased. When 394 nm excitation light was incident on the glass-ceramic containing 0.05% Eu2O3, red light of 614 nm wavelength emitted. We examined the relationship between the light emission mechanism and the crystal structure of the diopside-based glass-ceramic. We also discussed the applicability of the specimens prepared in this study as light emitting materials in various fields.

Photoluminescence Properties of Nano-Sized BaO–TiO2–SiO2 System-Based Glass-Ceramics Doped with Er2O3 and Eu2O3

2021 ◽  
Vol 21 (3) ◽  
pp. 1820-1825
Author(s):  
Yoorim Rho ◽  
Seunggu Kang
Keyword(s):  
Glass Ceramic ◽  
Treatment Process ◽  
Red Light ◽  
Glass Ceramics ◽  
Light Transmittance ◽  
Crystal Phase ◽  
Photoluminescence Properties ◽  
Excitation Light ◽  
Prepared Glass ◽  
Luminescence Characteristics

The crystal phase of fresnoite (Ba2TiSi2O8) produced from BaO–TiO2–SiO2 (hereinafter referred to as BTS) has nonlinear optical properties and is capable of emitting ultraviolet light. It can also be utilized in various fields, such as optical communications and optoelectronic devices. In this study, Er and Eu were added to BTS-based glass and a glass-ceramic containing a nano-sized fresnoite crystal phase was prepared through an appropriate heat treatment process. The relationships among the type of crystal phase, the microstructure, the light transmittance capabilities and the PL characteristics of the prepared glass-ceramic were analyzed. In the glass-ceramic of BTS doped with Er, 428 nm light was emitted when excitation light with a 268 nm wavelength was applied, while in the glass-ceramic of BTS doped with Eu, 613 nm red light was emitted when excitation light with a wavelength 394 nm was supplied. The produced fresnoite-based glass-ceramic exhibits transparency and luminescence characteristics due to the nano-sized crystal phase. Therefore, it is likely to find use in various fields in the future.

Crystallization Behavior and Microstructure of B2O3-Al2O3-SiO2 Glass-Ceramics

2008 ◽  
Vol 51 ◽  
pp. 149-154
Author(s):  
Han Ning Xiao ◽  
Tao Sun ◽  
Hua Bin Liu ◽  
Yin Cheng
Keyword(s):  
Activation Energy ◽  
Metal Oxides ◽  
Crystalline Phase ◽  
Crystallization Behavior ◽  
Glass Ceramics ◽  
Earth Metal ◽  
Crystallization Activation Energy ◽  
Alkali Earth Metal ◽  
Alkali Earth ◽  
Bulk Crystallization

The influences of B2O3/SiO2 ratio and different alkali earth metal oxides MO (M= Ba, Mg, Ca) on the crystallization behavior of B2O3-Al2O3-SiO2 (BAS) glass were investigated by means of DSC, XRD and SEM. With the reduction of B2O3/SiO2 ratio, the crystallization activation energy increases at first and then decreases, reaching the minimum value of 375.4 kJ·mol-1 when the B2O3/SiO2 ratio is 2.2. The crystalline indices (n) are all more than 4, which indicates that the glass is in bulk crystallization. When the glass was heated to 800°C, the primary precipitated crystalline phase was Al4B2O9. With the increase of temperature up to 1100°C, Al18B4O33 and Al5BO9 appeared and became the major crystalline phases in BAS glass-ceramics.

scholarly journals Mutual Influence of Special Components in Baotou Steel Blast Furnace Slag on the Crystallization Behavior of Glass

2012 ◽  
Vol 2012 ◽  
pp. 1-6
Author(s):  
Yici Wang ◽  
Qi Jiang ◽  
Guoping Luo ◽  
Wenwu Yu ◽  
Yan Ban
Keyword(s):  
Blast Furnace ◽  
Blast Furnace Slag ◽  
Crystallization Behavior ◽  
Mutual Influence ◽  
Raw Materials ◽  
Glass Ceramics ◽  
Nucleating Agent ◽  
Crystal Phase ◽  
Furnace Slag ◽  
Crystallization Of Glass

In the process of glass-ceramics prepared with Baotou steel blast furnace slag, quartz sand, and other raw materials by melting method, the mutual influence of the special components such as CaF2, REXOY, TiO2, K2O, and Na2O in the blast furnace slag on the crystallization behavior of parent glass was investigated using differential thermal analysis (DTA) and X-ray diffraction (XRD). The results show that the special components in slag can reduce the crystallization temperature and promote crystallization of glass phase, which belongs to surface crystallization of glass, and they cannot play the role of the nucleating agent; the major crystal phase composed of diopside, diopside containing aluminum and anorthite, is slightly different from the expected main crystal phase of diopside. Therefore, the nucleating agents of proper species and quantity must be added into the raw materials in order to obtain glass-ceramics. The results have important theoretical guidance meaning for realizing industrial production of Baotou steel blast furnace slag glass-ceramics preparation.

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.

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.

Nucleation Agent Choice of Li2O–Al2O3–SiO2 Glass Ceramic Having Ideal Micro Spherical Crystal Grains

2011 ◽  
Vol 311-313 ◽  
pp. 1332-1335
Author(s):  
Hao Lv ◽  
Yao Ming Ding ◽  
Ai Mei Liu ◽  
Ju Fang Tong ◽  
Xu Nong Yi ◽  
...  
Keyword(s):  
Glass Ceramic ◽  
Crystallization Behavior ◽  
Nucleating Agent ◽  
Nucleating Agents ◽  
X Ray Diffraction ◽  
Nucleation Agent ◽  
X Ray ◽  
Spherical Crystal ◽  
Crystal Grains ◽  
Scanning Electron

The nucleation and crystallization of Li2O-Al2O3-SiO2(LAS) glass ceramic with one(P2O5, TiO2, ZnF2) and two nucleating agents(P2O5+TiO2, P2O5+ZnF2) are investigated by the differential thermal analysis(DTA)，X-ray diffraction(XRD) and the scanning electron microscopy(SEM). Research results show that the LAS glass ceramic with nucleating agent of P2O5can obtain ideal micro spherical crystal grains and the crystallization behavior can be better controlled.

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.

scholarly journals PHYSICO-MECHANICAL AND THERMOPHYSICAL PROPERTIES OF FOAM- GLASS CERAMICS BASED ON SILICA ROCK

2019 ◽  
Vol 4 (5) ◽  
pp. 8-15
Author(s):  
В. Ерофеев ◽  
Vladimir Erofeev ◽  
А. Родин ◽  
Aleksandr Rodin ◽  
А. Кравчук ◽  
...  
Keyword(s):  
Glass Ceramic ◽  
Power Plants ◽  
Building Materials ◽  
Heating Temperature ◽  
Glass Melting ◽  
Foam Glass ◽  
Glass Ceramics ◽  
Mechanical And Thermal Properties ◽  
Ceramic Building ◽  
Foam Glass Ceramics

Obtaining the foam-glass ceramic building materials bypassing the process of high-temperature glass melting and the use of local rocks as raw materials, which can significantly reduce the cost of the final product, is an urgent task of modern building materials science. The aim of this work is to study the physical, mechanical and thermal properties of foam- glass ceramic building materials obtained by one heating of the mixture consisting of silica-containing rock (tripoli) and soda ash. The developed heat-insulating building materials have an average density of 200 to 600 kg/m3, compressive strength of 1.2 to 9.8 MPa, thermal conductivity of 0.053 to 0.065 W/m °C. Studies establishes a rational ratio of components in the composition of foam glass ceramics based on silica rock. In the production of foam materials, the heating rate of the charge should vary from 3 to 4.5 ° C / min, and the maximum heating temperature from 800 to 850 ° C. The developed material will expand the range of thermal insulation building materials and can be used in the construction of industrial and civil facilities, nuclear power plants, in the gas and oil industry.

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