Microcrystal Growth in Heat-Treating Process for Europium Ions Doped Aluminosilicate Glasses

Eu doped YAG glass ceramics containing single phase of YAG micro-cryatals have been obtained by heat-treating the aluminosilicate precursor glasses. The primary crystallite size of YAG phase is calculated to be ~46 nm and the crystal grains grow with preffered orientation (444) in the internal network. The average secondary particle size is estimated to be ~8μm and the larger grain size is due to the particle aggregation. The pilotaxitic texture of YAG glass ceramics presented in SEM micrograph, can increase yield strength and tensile strength of the sample effectively. The emission spectrum of Eu doped YAG glass ceramics consists of a broad blue emission band and several narrow emission bands, indicating the coexistence of Eu3+ and Eu2+ ions in YAG glass ceramics.

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Samarium Ions Doped Yttrium Aluminium Garnet Glass Ceramics

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.531-532.216 ◽

2012 ◽

Vol 531-532 ◽

pp. 216-219

Author(s):

Jie Yang ◽

Xiao Liu ◽

Bin Zhai ◽

Zhi Qiang Wang ◽

Xin Zhao ◽

...

Keyword(s):

Single Phase ◽

Glass Ceramics ◽

Heat Treating ◽

Rare Earth Ions ◽

Yttrium Aluminium Garnet ◽

Stark Splitting ◽

Optical Glasses ◽

Yttrium Aluminium ◽

Internal Network ◽

The Matrix

Sm3+doped YAG glass ceramics containing single phase of YAG micro-crystals have been obtained by heat-treating the aluminosilicate precursor glasses. The YAG crystals grow with several preferred orientations and a dominant one (444) in the matrix, and present microcrystal sizes in the range of 3~15µm. The pilotaxitic texture existed in internal network of the YAG glass ceramics can increase yield strength and tensile strength of the sample effectively. Typical visible transition emissions of Sm3+have been observed in the YAG glass ceramics under the excitation of short-wavelength visible light, and the spectral intensity ratio between the electric dipole4G5/2→6H9/2and the magnetic dipole4G5/2→6H5/2transitions is lower than the values reported in the optical glasses specifying the enhanced symmetric nature in the Sm3+doped YAG glass ceramics. The obvious Stark splitting exhibited in emission spectrum manifests that rare-earth ions have been incorporated into YAG lattices.

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COPPER ALLOY No. 230

Alloy Digest ◽

10.31399/asm.ad.cu0252 ◽

1972 ◽

Vol 21 (3) ◽

Keyword(s):

Fracture Toughness ◽

Corrosion Resistance ◽

Shear Strength ◽

High Temperature ◽

Physical Properties ◽

Tensile Properties ◽

Copper Alloy ◽

Single Phase ◽

Heat Treating ◽

Temperature Performance

Abstract COPPER ALLOY No. 230 is a single-phase brass containing 15% zinc which is the most widely used of the low zinc brasses. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and shear strength as well as fracture toughness and creep. It also includes information on low and high temperature performance, and corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Cu-252. Producer or source: Brass mills.

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METGLAS ALLOY 2826

Alloy Digest ◽

10.31399/asm.ad.ni0235 ◽

1976 ◽

Vol 25 (11) ◽

Keyword(s):

Magnetic Properties ◽

Metallic Glass ◽

Liquid State ◽

Single Phase ◽

Heat Treating ◽

High Permeability ◽

Metallic Material ◽

Nickel Iron ◽

Rapid Quench ◽

Chemical Corporation

Abstract METGLAS Alloy 2826 (Fe40Ni40P14B6) is a ferromagnetic, high permeability, nickel-iron metallic glass which, when appropriately annealed, yields a material similar to the higher nickel containing permalloys in magnetic properties. Alloy 2826 is a single phase, opaque metallic material with a glass-like structure obtained by a very rapid quench from the liquid state. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as creep. It also includes information on forming and heat treating. Filing Code: Ni-235. Producer or source: Allied Chemical Corporation.

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A new langbeinite-type phosphate K2GdHf(PO4)3: synthesis, crystal structure, band structure and luminescence properties

Acta Crystallographica Section C Structural Chemistry ◽

10.1107/s2053229620009857 ◽

2020 ◽

Vol 76 (8) ◽

pp. 771-778

Author(s):

Hua Nan ◽

Li Chen ◽

Rui-Juan Zhang ◽

Dan Zhao

Keyword(s):

Optical Transition ◽

Blue Emission ◽

Large Family ◽

Luminescence Properties ◽

X Ray Diffraction ◽

Blue Emission Band ◽

Light Emitting ◽

Direct Band ◽

Cie Chromaticity ◽

White Light Emitting Diodes

Langbeinite-type compounds are a large family that include phosphates, sulfates and arsenates, and which are accompanied by interesting physical properties. This work reports a new disordered langbeinite-type compound, K2GdHf(PO4)3 [dipotassium gadolinium hafnium tris(phosphate)], and its structure as determined by single-crystal X-ray diffraction. Theoretical studies reveal that K2GdHf(PO4)3 is an insulator with a direct band gap of 4.600 eV and that the optical transition originates from the O-2p→Hf-5d transition. A Ce3+-doped phosphor, K2Gd0.99Ce0.01Hf(PO4)3, was prepared and its luminescence properties studied. With 324 nm light excitation, a blue emission band was observed due to the 5d 1→4f 1 transition of Ce3+. The average luminescence lifetime was calculated to be 5.437 µs and the CIE chromaticity coordinates were (0.162, 0.035). One may expect that K2Gd0.99Ce0.01Hf(PO4)3 can be used as a good blue phosphor for three-colour white-light-emitting diodes (WLEDs).

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Exciton-phonon interactions observed in blue emission band in Te-delta-doped ZnSe

Journal of Applied Physics ◽

10.1063/1.2966697 ◽

2008 ◽

Vol 104 (3) ◽

pp. 033531 ◽

Cited By ~ 2

Author(s):

M. Jo ◽

Y. Hayashi ◽

H. Kumano ◽

I. Suemune

Keyword(s):

Emission Band ◽

Blue Emission ◽

Blue Emission Band

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Preparation of Delafossite CuYO2 by Metal-citric Acid Complex Decomposition Method

MRS Proceedings ◽

10.1557/proc-1166-n03-13 ◽

2009 ◽

Vol 1166 ◽

Cited By ~ 2

Author(s):

Keishi Nishio ◽

Tomomi Okada ◽

Naoto Kikuchi ◽

Satoshi Mikusu ◽

Tsutomu Iida ◽

...

Keyword(s):

Thermal Decomposition ◽

Citric Acid ◽

Single Phase ◽

Raw Materials ◽

Chelating Agent ◽

Amorphous Powder ◽

Heat Treating ◽

Acid Complex ◽

Synthesis Conditions ◽

Starting Solution

AbstractDelafossite CuYO2 and Ca doped CuYO2 were prepared by thermal decomposition of a metal-citric acid complex. The starting solution consisted of Cu acetate, Y acetate and Ca acetate as the raw materials. Citric acid was used as the chelating agent, and acetic acid and distilled water were mixed as a solvent. The starting solutions were heated at 723 K for 5 h after drying at 353 K. The obtained powders were amorphous and single phase of orthorhombic Cu2Y2O5 was obtained by heat-treated the amorphous powder at a temperature range between 1073 and 1373 K for 3 h in air. Furthermore, Heat-treating the obtained orthorhombic Cu2Y2O5 at above 1373 K in air caused it to decompose into Y2O3, CuO and Cu2O. On the other hand, the sample powder prepared from a starting solution without citric acid, i.e., single phase of orthorhombic Cu2Y2O5 could not be obtained under the same synthesis conditions as that for a solution with citric acid. We were able to obtain delafossite CuYO2 and Ca doped CuYO2 from orthorhombic Cu2Y2O5 under a low O2 pressure atmosphere at above 1223 K. The obtained delafossite CuYO2 composed hexagonal and rhombohedral phases. The color of the CuYO2 powder was light brown and that of Ca-doped CuYO2 was light green. Diffraction peaks in the XRD pattern were slightly shifted by doping Ca for CuYO2, and these peaks shifted toward to a high diffraction angle with an increasing amount of doped Ca. From these results, we concluded that Ca doped delafossite CuYO2 could be obtained by thermal decomposition of a metal-citric acid complex.

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Low Temperature Photoluminescence Characteristics of Chemically Synthesized Indium Doped Zinc Oxide Nanostructures

Journal of Nanoscience and Nanotechnology ◽

10.1166/jnn.2008.18422 ◽

2008 ◽

Vol 8 (12) ◽

pp. 6538-6544 ◽

Cited By ~ 5

Author(s):

A. Escobedo Morales ◽

R. Aceves ◽

U. Pal ◽

J. Z. Zhang

Keyword(s):

Zinc Oxide ◽

Blue Emission ◽

Visible Range ◽

Zinc Oxide Nanostructures ◽

Blue Emission Band ◽

Oxide Nanostructures ◽

Indium Doping ◽

Different Temperatures ◽

Excitonic Emission ◽

Donor States

Photoluminescence (PL) emission and excitation (EPL) spectra of un-doped and indium (1%) doped 1D zinc oxide nanostructures are studied at different temperatures. The nanostructures reveal a blue emission band attributed to localized donor states. Indium doping enhances the blue emission. While at low temperatures (<50 K) PL spectra are dominated by the emission attributed to the recombination of excitons bound to neutral donors (D0,X), at higher temperatures (>100 K), defect related emissions in the visible range dominate over the excitonic emission. Temperature dependence measurements on the doped sample reveal that (D0,X) emission energies obey the Varshni's formula with fitting constants α = 8.4±0.3 × 10−4 eV/K and β = 650±40 K. The (D0,X) emission intensity decays exponentially with temperature.

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Nanostructured CaWO4, CaWO4 : Pb2+ and CaWO4 : Tb3+ Particles: Polyol-Mediated Synthesis and Luminescent Properties

Journal of Nanoscience and Nanotechnology ◽

10.1166/jnn.2007.18049 ◽

2007 ◽

Vol 7 (2) ◽

pp. 602-609 ◽

Cited By ~ 1

Author(s):

Zhenling Wang ◽

Guangzhi Li ◽

Zewei Quan ◽

Deyan Kong ◽

Xiaoming Liu ◽

...

Keyword(s):

Electron Microscopy ◽

Uv Light ◽

Blue Emission ◽

Luminescent Properties ◽

Spherical Particles ◽

Sem Images ◽

Blue Emission Band ◽

Transmission Electron ◽

Characteristic Emission ◽

20 Nm

Nano-submicrostructured CaWO4, CaWO4 : Pb2+ and CaWO4 : Pb3+ particles were prepared by polyol method and characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), Fourier transform infrared spectra (FT-IR), thermogravimetry-differential thermal analysis (TG-DTA), photoluminescence (PL), cathodoluminescence (CL) spectra and PL lifetimes. The results of XRD indicate that the as-prepared samples are well crystallized with the scheelite structure of CaWO4. The FE-SEM images illustrate that CaWO4 and CaWO4 : Pb2+ and CaWO4 : Tb3+ powders are composed of spherical particles with sizes around 260, 290, and 190 nm respectively, which are the aggregates of smaller nanoparticles around 10–20 nm. Under the UV light or electron beam excitation, the CaWO4 powders exhibits a blue emission band with a maximum at about 440 nm. When the CaWO4 particles are doped with Pb2+, the intensity of luminescence is enhanced to some extent and the luminescence band maximum is red shifted to 460 nm. Tb3+-doped CaWO4 particles show the characteristic emission of Tb3+ 5D4–7FJ (J = 6 – 3) transitions due to an energy transfer from WO42− groups to Pb3+.

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Luminescence of SrY2O4:Eu3+ associated with defects

Journal of Materials Research ◽

10.1557/jmr.2010.0283 ◽

2010 ◽

Vol 25 (11) ◽

pp. 2120-2124 ◽

Cited By ~ 2

Author(s):

Jia Zhang ◽

Yuhua Wang

Keyword(s):

Solid State ◽

Solid State Reaction ◽

Vacuum Ultraviolet ◽

Sol Gel ◽

Blue Emission ◽

Solid State Reaction Method ◽

Excitation Spectra ◽

Blue Emission Band ◽

Gel Method ◽

Sol Gel Method

SrY2O4:Eu3+ phosphors were synthesized by both the solid-state reaction method and the sol-gel method, and their photoluminescence in vacuum ultraviolet (VUV) and the ultraviolet (UV) region were evaluated. The excitation spectra of SrY2O4:Eu3+ phosphors prepared by solid-state reaction show another excitation band centered at 324 nm except for the charge-transfer bands (CTB) of Eu3+ when monitored at 610 nm, and a blue emission band around 406 nm is observed when excited at 324 nm, which could be associated with defects. Both the excitation and emission bands mentioned above disappear when the samples were prepared by the sol-gel method. SrY1.98O4:0.02Eu3+ phosphors synthesized by the sol-gel method exhibit a higher emission intensity under 147 nm excitation compared with solid-state reaction technology. The main reason could be that the samples prepared by the solution-based route have more regular and uniform morphologies.

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