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Highly crystalline Y_(3)Al_(5)O_(12):Ce^(3+)phosphor-in-silica glass ceramics for high-power solid-state lighting

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Journal of Rare Earths 2024年第11期42卷 2051-2057,I0002页

作者： Shisheng Lin Hang Lin Hongyi Yang Pengfei Wang Ping Sui Ju Xu Yao Cheng Yuansheng Wang Key Laboratory of Optoelectronic Materials Chemistry and Physics Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou350002China Fujian Science&Technology Innovation Laboratory for Optoelectronic Information of China Fuzhou350108China Xiamen Institute of Rare-earth Materials Haixi InstitutesChinese Academy of SciencesXiamen36100China College of Chemistry and Materials Science Fujian Normal UniversityFuzhou350007China

The pursuit of high-brightness solid-state lighting(SSL)stimulates the development of all-inorganic color converters with high *** is required that the fluorescent material is able to cope with the extreme condition generated from the irradiation of high-power-density excitation *** such,in this work,we developed a new composite color converter,i,e.,Y_(3)Al_(5)O_(12):Ce^(3+)phosphor-in-silica glass ceramic(YAG:Ce^(3+)PiSGC).Remarkably,the amorphous SiO_(2)matrix spontaneously transforms into tetragonal SiO_(2)crystallites during co-sintering with crystallization fraction reaching up to>90%(almost full ceramization).The activation energy for crystallization E_(c)and Avrami index n of amorphous silica oxide are 298.5 kJ/mol and 1.71,indicating the diffusion-controlled glass crystallization *** fabricated prototype high-power phosphor-converted white light-emitting diode(pc-wLED)and phosphor-converted white laser diode(pc-wLD)based on YAG:Ce^(3+)PiSGC show satisfactory photometric/colorimetric *** developed color co nverters have combined merits of environmental protection property,cost-effective manufacturing,good luminescent performance,and easy *** study highlights a new kind of opto-functional composite material and its application as an efficient color converter in high-power solid-state lightings.

关键词： glass ceramics Y_(3)Al_(5)O_(12):Ce^(3+) Laser-driven white light White light-emitting diode Rare earths

Synthesis of glass ceramics from kaolin and dolomite mixture

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International Journal of Minerals,Metallurgy and Materials 2017年第2期24卷 194-201页

作者： Mohamed Reda Boudchicha Fausto Rubio Slimane Achour Engineering Mechanics and Materials Laboratory Mechanical Engineering Department Faculty of Technology Universite 20 Aout 1955 de Skikda Skikda 21000 Algeria ceramics and glass Institute Consejo Superior de Investigaciones Cientificas Madrid 28049 Spain National Polytechnic School Constantine 25000 Algeria

Cordierite- and anorthite-based binary glass ceramics of the CaO-MgO-Al2O3-SiO2 （CMAS） system were synthesized by mixing local and abundant raw minerals （kaolin and doloma by mass ratio of 82/18）. A kinetics study reveals that the activation energy of crystalli- zation （Ea） calculated by the methods of Kissinger and Marotta are 438 kJ·mol^-1 and 459 kJ·mol^-1, respectively. The Avrami parameter （n） is estimated to be approximately equal to 1, corresponding to the surface crystallization mechanism. X-ray diffraction （XRD） analysis shows that the anorthite and cordierite crystals are precipitated from the parent glass as major phases. Anorthite crystals first form at 850℃, whereas the μ-cordierite phase appears after heat treatment at 950℃. Thereafter, the cordierite allotropically transforms to α-cordierite at 1000℃. Complete densification is achieved at 950℃; however, the density slightly decreases at higher temperatures, reaching a stable value of 2.63 kg·m^-3 between 1000℃ and 1100℃, The highest Vickers hardness of 6 GPa is also obtained at 950℃. However, a substantial decrease in hardness is recorded at 1000℃; at higher sintering temperatures, it slightly increases with increasing temperature as the ct-cordierite crystallizes.

关键词： glass ceramics kaolinite dolomite crystallization activation energy

Effects of ZnO,FeO and Fe_(2)O_(3)on the spinel formation,microstructure and physicochemical properties of augite-based glass ceramics

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International Journal of Minerals,Metallurgy and Materials 2023年第6期30卷 1207-1216页

作者： Shuai Zhang Yanling Zhang Shaowen Wu State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing 100083China

Augite-based glass ceramics were synthesised using ZnO,FeO,and Fe_(2)O_(3)as additives,and the spinel formation,matrix structure,crystallisation thermodynamics,and physicochemical properties were *** results showed that oxides resulted in numerous preliminary spinels in the glass ***,ZnO,and Fe_(2)O_(3)influenced the formation of spinel,while FeO simplified the glass *** and ZnO promoted bulk crystallisation of the parent *** adding oxides,the grains of augite phase were refined,and the relative quantities of augite crystal planes were also *** samples displayed good mechanical properties and chemical *** 2wt%ZnO-doping sample displayed the maximum flexural strength(170.3 MPa).Chromium leaching amount values of all the samples were less than the national standard(1.5 mg/L),confirming the safety of the *** conclusion,an appropriate amount of zinc-containing raw material is beneficial for the preparation of augite-based glass ceramics.

关键词： spinel network structure thermodynamics microstructure glass ceramics

Preparation and luminescence properties of Eu^(3+) doped oxyfluoride borosilicate glass ceramics

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Journal of Rare Earths 2012年第12期30卷 1195-1198页

作者：李艳红赵丽张永明马晶 School of Materials Science and Engineering Shenyang University of Chemical Technology

Oxyfluoride borosilicate glass with the molar composition of 60SiO2-15B2O3- 15Na2O-8CaF2-2NaF-0.25Eu2O3 was synthesized lay a traditional glass melting method. glass ceramics containing CaF2 nanocrystals were prepared by heat treating the glass samples at a temperature in the range of 6204580 ℃. The results of X-ray diffraction （XRD） indicated that the average crystallite size and the lattice constant of CaF2 nanocrystals increased with the heat treatment temperature increasing. The luminescence spectra showed that the emission intensity of Eu3＋ doped glass ceramics was stronger than that of the glass matrix, and increased with the heat treatment temperature increasing. The left edge of excitation band shifted to shorter wavelength in the glass ceramics. The local environments of Eu3＋ ions in the glass and glass ceramics were different.

关键词： oxyfluoride glass ceramics luminescence local environment rare earths

Sm^(3+) ions doped Sm_(2)Si_(2)O_(7)-based glass ceramics:Crystallization,luminescence and energy transfer process through heat treatment

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Journal of Rare Earths 2023年第8期41卷 1144-1152,I0001页

作者： M.Monisha M.S.Murari Dalal Abdullah Aloraini Aljawhara H.Almuqrin M.I.Sayyed Karunakara Naregundi Sudha D.Kamath Department of Physics Manipal Institute of TechnologyManipal Academy of Higher EducationManipal576104India Scientific Officer DST-PURSE ProgramMangalore UniversityMangalagangotriKarnataka574199India Department of Physics College of SciencePrincess Nourah Bint Abdulrahman UniversityP.O.Box 84428Riyadh11671Saudi Arabia Department of Physics Faculty of ScienceIsra UniversityAmmanJordan Centre for Application of Radioisotopes and Radiation Technology(CARRT) Mangalore UniversityMangalagangotriKarnataka574199India Centre for Advanced Research in Environmental Radioactivity(CARER) Mangalore UniversityMangalagangotriKarnataka574199India

Sm^(3+) ions incorporated Sm_(2)Si_(2)O_(7) crystalline phase formed in the aluminoborosilicate glass matrix synthesized via melting quenching technique followed by heat-treatment process is reported *** preliminary confirmation on the obtained glass ceramics was made through X-ray diffration(XRD) *** of non-bridging oxygens(NBOs) in the glass network and the modes of vibrations of network units we re analyzed through Fourier transform infrared spectroscopy(FTIR) *** morphology of heat-treated samples at varying temperatures was determined via a field emission scanning electron microscope(FESEM).The absorption studies on heat-treated samples signify the low bandgap values and high Urbach energy values due to improved crystallinity in the glass ***-Ofelt intensity parameters identified for visible absorption transitions follow the trend of Ω_(4)>Ω_(2)>Ω_(6).Excitation and emission studies on heat-treated samples show improvement in their intensities compared to the unheated base *** thermal quenching is observed at higher temperatures(540 and 580℃ for 3 h) of heat-treated *** based on luminescence spectra including radiative transition probability,stimulated emission cross-section and branching ratio show good results for glass ceramics prior to precursor *** lifetimes of Sm^(3+) ions(milliseconds) in the level ^(4)G_(5/2) are seen for glass *** coordinates suggest the reddish-orange emissions from prepared glass ***,Sm^(3+) doped Sm_(2)Si_(2)O_(7) glass ceramics are favorable materials for solid-state lighting and laser applications.

关键词： Sm^(3+)ions glass ceramics Luminescence spectra Stimulated emission cross-section Rare earths

Fabrication,microstructure,and optical properties of nanocrystalline transparent LAST glass ceramics containing CeO_2

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International Journal of Minerals,Metallurgy and Materials 2014年第4期21卷 401-407页

作者： Mohammad Sadegh Shakeri Materials and Energy Research Center (MERC)

In the present research, the effect of CeO2 dopant on the fabrication of transparent lithium aluminosilicate titanate （LAST） glass ceramics was investigated. Nanocrystallineβ-quartz solid solution （s.s.） was observed to be the main phase crystallized in this system. Com-parable refractive indices of the glassy matrix andβ-quartz s.s., as well as the incorporation of very fine grains size were determined as the main reasons for retaining the transparency of the glass ceramics. CeO2 was introduced as a suitable optical agent, playing a role as a network modifier in the glass ceramics, because it does not accelerate the growth process and retards the extended growth of crystals. Optical investi-gations indicate that the Fermi energy level, direct and indirect band gaps, and Urbach energy decrease with increasing nanocrystal content in the glassy matrix of specimens, which can be related to the expansion of conduction band, the enhancement of ionic bonds in the crystal lat-tice, and the enhancement of structural arrangement degree, respectively.

关键词： glass ceramics nanocrystals alurninosilicates titanates transparency optical properties

Preparation and Luminescence of Er^(3+) Doped Oxyfluoride glass ceramics Containing LaF_3 Nanocrystals

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Journal of Rare Earths 2006年第1期24卷 67-71页

作者：王瑾乔旭升樊先平王民权 Department of Materials Science and Engineering Zhejiang University Hangzhou 310027 China Department of Materials Science and Engineering Zhejiang University Hangzhou 310027 Chin Department of Materials Science and Engineering Zhejiang University Hangzhou 310027 ChinaState Key Laboratory of Silicon Materials Zhejiang University Hangzhou 310027 China

Er^3＋ doped transparent oxyfluoride glass ceramics version and near infrared luminescence behavior of Er^3＋ in containing LaF3 nanocrystals were prepared and the up-conglasses heat-treating time and temperature, the size （varied from 0 to 19 and glass ceramics were investigated. With increasing nm） and crystallinity （varied from 0 to 47%） of LaF3 nanocrystals in the glass ceramics are increased. The up-conversion luminescence intensity of Er^3＋ ions in the glass ceramics is much stronger than that in the glasses The near infrared emission of Er^3＋ ions in and increased significantly with increasing heat-treating time and temperature the glass ceramics is found to be similar to that in the glasses.

关键词： glass ceramics Er^3+ ions up-conversion and NIR emission rare earths

Effect of Y_2O_3 on the crystallization kinetics of TiO_2 nucleated LAS glass for the production of nanocrystalline transparent glass ceramics

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International Journal of Minerals,Metallurgy and Materials 2013年第5期20卷 450-455页

作者： Mohammad Sadegh Shakeri Materials and Energy Research Center (MERC) P.O. Box 31779-83634KarajIran

Crystallization kinetics of metastable B-quartz solid solution as a desirable phase for the production of trans- parent lithium aluminosilicate （LAS） glass ceramics was investigated in the presence of Y203. Accordingly, differential thermal analysis scans were performed thoroughly to study the mechanism of crystallization kinetics. The aim of this investigation is to discover the complicated mechanism of crystallization process in the presence of co-additives and ac- cordingly find a way for increasing the transparency of glass ceramics. It is shown that the bulk （3D） growth is intensively increased by the enhancement of Y203. Then again, reducing nucleation and increasing growth mechanisms were recog- nized for the LAS system in the presence of Y2O3. Results of the investigation illustrate that when co-additives are added to glasses, it is necessary to nucleate the optical component separately before the growth process.

关键词： glass ceramics lithium aluminosilicate yttria crystallization kinetics nanocrystals transparency

Oxy-Fluoride Borate Infrared Up-Conversion glass ceramics

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Journal of Rare Earths 2003年第S1期21卷 110-112页

作者：杨魁胜梁海莲程光孟健 School of Material and Chemical Engineering Changchun University of Science and Technology Key Laboratory of Rare Earth Chemistry and Physics ChangChun Institute of Applied ChemistryChinese Academy of Sciences

The processing parameters and infrared up-conversion properties of fluoroborate glass ceramics in composition of BaB_2O_4+AlF_3+BaF_2+PbF_2∶YbF_3+HoF_3 were reported. The emission spectrum was measured by Hitachi F-4500 spectrometer. The results show that three emission peaks located at 470,545 and 655 nm respectively are observed,(among) which the peak at 545 nm is the strongest. Photon absorption theory and energy transmission theory are used to explain the emission spectrum.

关键词： up-conversion luminescence glass ceramics Yb (3+)/Ho (3+) rare earths