Preparation and Luminescent Properties of 0.1%Ce3+:BaF2 Laser Ceramics by Vacuum Sintering

0.1% Ce3+:BaF2 powders were prepared by coprecipitation method. Then the transparent ceramics were prepared by vacuum sintering. The effectts of sintering temperature and holding time on transparent ceramics were studied. The results show that the 0.1% Ce3+:BaF2 powders prepared by coprecipitation are approximately spherical with the size ranging from 200~300nm and good dispersion. The maximum light transmittance of the 0.1% Ce3+:BaF2 transparent ceramics reaches 69.2% when the sintering temperature is 1275°C. The fluorescence intensity of the transparent ceramics enhances with the increase of the sintering temperature. There are two characteristic f-f transition emission peaks at 610nm and 650nm when the excitation peak is at 290nm. The maximum transparency of 71.4% emerges when the holding time is 6h at 1275°C and the fluorescence intensity reaches the maximum. The 528nm (5D1→2F7/2) appears when excitated by the 524nm excitation light.

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Preparation and Properties of Ce3+:BaF2 Transparent Ceramics by Vacuum Sintering

Journal of Nanoscience and Nanotechnology ◽

10.1166/jnn.2016.11873 ◽

2016 ◽

Vol 16 (4) ◽

pp. 3985-3989 ◽

Cited By ~ 5

Author(s):

Junming Luo ◽

Lifang Ye ◽

Jilin Xu

Keyword(s):

Cleavage Fracture ◽

Fluorescence Spectra ◽

Secondary Phase ◽

Fracture Morphology ◽

Light Transmittance ◽

Transparent Ceramics ◽

Vacuum Sintering ◽

Maximum Light ◽

Chemical Coprecipitation ◽

Chemical Coprecipitation Method

Ce0.001Ba0.999F2.001 powders were prepared by a chemical coprecipitation method using Ba(NO3)2, KF · 2H2O and Ce(NO3)3 · 6H2Oasraw materials. Ce0.001Ba0.999F2.001 transparent ceramics were prepared by vacuum sintering. The results show that the Ce0.001Ba0.999F2.001 powders were blocky, and both powdered and sintered transparent ceramics were composed of BaF2 phases without the secondary phase. The maximum light transmittance of the Ce0.001Ba0.999F2.001 transparent ceramics reached 55%. The fracture morphology shows a cleavage fracture with a few micropores. The fluorescence spectra show that the Ce0.001Ba0.999F2.001 powders displayed emissions at 410 nm, 480 nm and 620 nm under 275 nm excitation. The Ce0.1Ba0.9F2.1 transparent ceramics displayed emissions at 450 nm and 620 nm under 294 nm excitation.

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Optical Properties and Microstructure of Mn: MgAl2O4 Transparent Ceramic after HIP Treatment

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.368-372.417 ◽

2008 ◽

Vol 368-372 ◽

pp. 417-419

Author(s):

Yue Feng Sun ◽

Tie Cheng Lu ◽

Xue Jun Wang ◽

Mu Yun Lei ◽

Cun Xin Huang

Keyword(s):

Optical Properties ◽

Hot Isostatic Pressing ◽

Wavelength Region ◽

Optical Transmittance ◽

Light Transmittance ◽

Transparent Ceramics ◽

Light Wavelength ◽

Vacuum Sintering ◽

Two Samples ◽

Mn Doped

5.0at% and 10.0at% Mn-doped MgAl2O4 transparent ceramics have been prepared through vacuum sintering (1750°C /2h) and subsequent hot isostatic pressing (HIP) (1650°C /2h). The effect of microstructure on the light transmittance of the sintered MgAl2O4 is discussed. Results showed that the grains became dense and grain boundary became clear and most of pores inside and between grains were removed, so the transmittance of two samples increased. The optical transmittance of the 5.0at% specimens was increased by one times in the visible light wavelength region. HIP treatment has a great effect on improving the transparency of samples with low doping concentrations.

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Fabrication, Microstructure, and Luminescent Properties of Ce3+ -Doped Lu3 Al5 O12 (Ce:LuAG) Transparent Ceramics by Low-Temperature Vacuum Sintering

Journal of the American Ceramic Society ◽

10.1111/jace.12231 ◽

2013 ◽

Vol 96 (6) ◽

pp. 1930-1936 ◽

Cited By ~ 31

Author(s):

Jian Xu ◽

Ying Shi ◽

Jianjun Xie ◽

Fang Lei

Keyword(s):

Low Temperature ◽

Luminescent Properties ◽

Transparent Ceramics ◽

Vacuum Sintering

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Preparation and Properties of Up-Conversion Luminescent NaYF4:Yb3+, Er3+ Ceramics

Materials Science Forum ◽

10.4028/www.scientific.net/msf.848.262 ◽

2016 ◽

Vol 848 ◽

pp. 262-271

Author(s):

Wen Yan Cheng ◽

Shi Jia Gu ◽

Bei Ying Zhou ◽

Lian Jun Wang ◽

Wei Luo ◽

...

Keyword(s):

Fluorescence Intensity ◽

Sintering Temperature ◽

Holding Time ◽

X Ray Diffraction ◽

X Ray ◽

Ceramic Samples ◽

Plasma Sintering ◽

Spark Plasma ◽

Crystal Phases ◽

Co Doped

A series of ytterbium and erbium co-doped sodium yttrium fluoride (NaYF4:Yb3+, Er3+) ceramics have been successfully prepared by pressureless sintering. The ceramic samples were characterized by X-ray diffraction (XRD), photoluminescence (PL), density and field emission scanning electron microscope (FESEM). The results showed that the phases of the NaYF4:Yb3+, Er3+ ceramic samples transformed when the sintering temperature was changed. The ceramic samples sintered below 600 oC contained both cubic α-NaYF4:Yb3+, Er3+ and hexagonal β-NaYF4:Yb3+, Er3+. The sample sintered at 600oC is the pure hexagonal β-NaYF4:Yb3+, Er3+. When the sintering temperature is above 600 oC, the ceramic samples present the α-NaYF4:Yb3+, Er3+ again. The fluorescence intensity increased firstly and then decreased with the sintering temperature increasing. The luminous intensity of the sample sintered at 600 oC was the highest. The densities of as-prepared ceramic sample increased with the sintering temperature rising. The samples sintered at 600 oC with different holding time possessed the similar crystal phases (β-NaYF4:Yb3+, Er3+) and fluorescence intensity. As the holding time increased, the densities of the samples increased. To obtain more dense ceramics, the ceramics using β-NaYF4:Yb3+, Er3+ powders were prepared by spark plasma sintering (SPS). The maximum relative density reached 97%.

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Influence of Sintering Process on Microstructure and Mechanical Properties of Ti(C,N)-Based Cermet

Materials ◽

10.3390/ma13183938 ◽

2020 ◽

Vol 13 (18) ◽

pp. 3938

Author(s):

Kaixun Ji ◽

Yanxin Meng ◽

Fuzeng Wang ◽

Yousheng Li

Keyword(s):

Mechanical Properties ◽

Sintering Temperature ◽

Holding Time ◽

Sintering Process ◽

X Ray Diffraction ◽

Vacuum Sintering ◽

Material Microstructure ◽

Cermet Material ◽

Hardness Tester ◽

Microstructure And Mechanical Properties

In this study, a Ti(C,N)-based cermet material was prepared through vacuum sintering. The research also investigates how holding time and maximum sintering temperature influence the material microstructure and mechanical properties. X-ray diffraction (XRD), energy dispersive spectroscopy (EDS) were used to analyze the composition of the cermet. The microstructure of the cermet was analyzed and examined using a scanning electron microscope (SEM). A Vickers hardness tester was used to test the mechanical properties of the materials. As indicated by testing results, the hardness of the material decreases as the temperature of sintering increases, and its fracture toughness increases gradually as holding time increases. Ti(C,N)-based cermet manifested the optimal mechanical properties when sintering was conducted under 1400 °C with 80 min of holding time. Moreover, the material microstructure is significantly affected by the sintering process. The grain size of Ti(C,N) cermets increases as the sintering temperature increases. The microstructure tends to be uniform and the complete core-rim structures are established as the holding time increases.

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Transparent Lu2O3:Eu Ceramics

MRS Proceedings ◽

10.1557/opl.2011.1205 ◽

2011 ◽

Vol 1341 ◽

Cited By ~ 2

Author(s):

Zachary M. Seeley ◽

Joshua D. Kuntz ◽

Nerine J. Cherepy ◽

Stephen A. Payne

Keyword(s):

Sintering Temperature ◽

Hot Isostatic Pressing ◽

High Vacuum ◽

Light Yield ◽

High Energy ◽

Stopping Power ◽

Transparent Ceramics ◽

Vacuum Sintering ◽

Lutetium Oxide ◽

High Light Yield

ABSTRACTWe are developing highly transparent ceramic oxide scintillators for high energy (MeV) radiography screens. Lutetium oxide doped with europium (Lu2O3:Eu) is the material of choice due to its high light yield and stopping power. As an alternative to hot-pressing, we are utilizing vacuum sintering followed by hot isostatic pressing (HIP). Nano-scale starting powder was uniaxially pressed into compacts and then sintered under high vacuum, followed by HIP’ing. Vacuum sintering temperature proved to be a critical parameter in order to obtain highly transparent Lu2O3:Eu. Under-sintering resulted in open porosity disabling the driving force for densification during HIP’ing, while over-sintering lead to trapped pores in the Lu2O3:Eu grain interiors. Optimal vacuum sintering conditions allowed the pores to remain mobile during the subsequent HIP’ing step which provided enough pressure to close the pores completely resulting in fully-dense highly transparent ceramics. Currently, we have produced 3 mm thick by 4.5 cm diameter ceramics with excellent transparency, and anticipate scaling to larger sizes while maintaining comparable optical properties.

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Optimization of Sintering Process of Alumina Ceramics Using Response Surface Methodology

Sustainability ◽

10.3390/su13126739 ◽

2021 ◽

Vol 13 (12) ◽

pp. 6739

Author(s):

Darko Landek ◽

Lidija Ćurković ◽

Ivana Gabelica ◽

Mihone Kerolli Mustafa ◽

Irena Žmak

Keyword(s):

Response Surface Methodology ◽

Response Surface ◽

Heating Rate ◽

Sintering Temperature ◽

Nonlinear Models ◽

Slip Casting ◽

Holding Time ◽

Alumina Ceramics ◽

Aqueous Suspensions ◽

Temperature Heating

In this work, alumina (Al2O3) ceramics were prepared using an environmentally friendly slip casting method. To this end, highly concentrated (70 wt.%) aqueous suspensions of alumina (Al2O3) were prepared with different amounts of the ammonium salt of a polycarboxylic acid, Dolapix CE 64, as an electrosteric dispersant. The stability of highly concentrated Al2O3 aqueous suspensions was monitored by viscosity measurements. Green bodies (ceramics before sintering) were obtained by pouring the stable Al2O3 aqueous suspensions into dry porous plaster molds. The obtained Al2O3 ceramic green bodies were sintered in the electric furnace. Analysis of the effect of three sintering parameters (sintering temperature, heating rate and holding time) on the density of alumina ceramics was performed using the response surface methodology (RSM), based on experimental data obtained according to Box–Behnken experimental design, using the software Design-Expert. From the statistical analysis, linear and nonlinear models with added first-order interaction were developed for prediction and optimization of density-dependent variables: sintering temperature, heating rate and holding time.

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Structure, Luminescence, and Magnetic Properties of Crystalline Manganese Tungstate Doped with Rare Earth Ion

Materials ◽

10.3390/ma14133717 ◽

2021 ◽

Vol 14 (13) ◽

pp. 3717

Author(s):

Jae-Young Jung ◽

Soung-Soo Yi ◽

Dong-Hyun Hwang ◽

Chang-Sik Son

Keyword(s):

Magnetic Field ◽

Rare Earth ◽

Sintering Temperature ◽

Luminescent Properties ◽

Concentration Quenching ◽

Rare Earth Ions ◽

Precipitation Method ◽

Rare Earth Ion ◽

Co Precipitation ◽

Quenching Phenomenon

The precursor prepared by co-precipitation method was sintered at various temperatures to synthesize crystalline manganese tungstate (MnWO4). Sintered MnWO4 showed the best crystallinity at a sintering temperature of 800 °C. Rare earth ion (Dysprosium; Dy3+) was added when preparing the precursor to enhance the magnetic and luminescent properties of crystalline MnWO4 based on these sintering temperature conditions. As the amount of rare earth ions was changed, the magnetic and luminescent characteristics were enhanced; however, after 0.1 mol.%, the luminescent characteristics decreased due to the concentration quenching phenomenon. In addition, a composite was prepared by mixing MnWO4 powder, with enhanced magnetism and luminescence properties due to the addition of dysprosium, with epoxy. To one of the two prepared composites a magnetic field was applied to induce alignment of the MnWO4 particles. Aligned particles showed stronger luminescence than the composite sample prepared with unsorted particles. As a result of this, it was suggested that it can be used as phosphor and a photosensitizer by utilizing the magnetic and luminescent properties of the synthesized MnWO4 powder with the addition of rare earth ions.

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Thermoelectric Properties of n-Type 90% Bi2Te3+10%Bi2Se3 Thermoelectric Materials Produced by Melt Spinning Method and Sintering

Materials Science Forum ◽

10.4028/www.scientific.net/msf.534-536.161 ◽

2007 ◽

Vol 534-536 ◽

pp. 161-164 ◽

Cited By ~ 3

Author(s):

Taek Soo Kim ◽

Byong Sun Chun

Keyword(s):

Solid Solutions ◽

Thermoelectric Materials ◽

Figure Of Merit ◽

Melt Spinning ◽

Bending Strength ◽

Sintering Temperature ◽

Thermoelectric Figure Of Merit ◽

Vacuum Sintering ◽

Thermoelectric Figure ◽

Sintering Processes

N-type Bi2Te3-Sb2Te3 solid solutions doped with CdCl2 was prepared by melt spinning, crushing and vacuum sintering processes. Microstructure, bending strength and thermoelectric property were investigated as a function of the doping quantity from 0.03wt.% to 0.10wt.% and sintering temperature from 400oC to 500oC, and finally compared with those of conventionally fabricated alloys. The alloy showed a good structural homogeneity as well as bending strength of 3.88Kgf/mm2. The highest thermoelectric figure of merit was obtained by doping 0.03wt.% and sintering at 500oC.

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