Photoluminescence, thermoluminescence, and cathodoluminescence of optimized cubic Gd2O3:Bi phosphor powder

Phosphor powder and phosphor-binder mixtures are successfully employed for temperature calibration measurements by using laser-induced phosphorescence (LIP) technique with an emphasis on higher precisions and accuracies than other non-intrusive methods. The phosphorescence intensities are used to perform these calibrations in three different strategies. The influence of laser power regular changes on particles heating and the calibration analyses is also carried out. A pulsed laser at 355 nm was used for exciting specimens of the phosphor powder as well as the phosphor-binder mixtures. The laser beam was directed onto the specimens and varied in three laser power levels (LPLs). The samples were kept in an oven with temperatures ranging from room temperature up to 1800 °C. The three strategies which are expressed in terms of non-dimensional intensity versus wavelength (NDI-W), normalised intensity (NI) and intensity ratio (IR) were used for the calibration assessments. A modified IR was compared with two different IRs. A precision of around ± (0.50-1.41)% was attained for different calibration methods. This research confirmed that these calibrations are possible using three different strategies, given high precisions and accuracies. The laser power alternations influenced the NI and do affect neither the NDI-W nor the IR curves. The laser radiation does not play any role for heating the particles of the studied powder.

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Development of New Glass Phosphor for Multimodal Artifact Metrics Applicable for Ceramics

Materials Science Forum ◽

10.4028/www.scientific.net/msf.940.109 ◽

2018 ◽

Vol 940 ◽

pp. 109-113

Author(s):

Masaki Fujikawa ◽

Mariko Hara ◽

Shingo Fuchi

Keyword(s):

Emission Intensity ◽

Base Material ◽

Optical Excitation ◽

Observation Point ◽

Phosphor Powder ◽

Novel Approach ◽

New Type ◽

Glass Phosphor ◽

Feature Information ◽

Different Color

Multi-modal artifact metrics, an anti-counterfeiting technique, was created based on the concept of multi-modal biometrics and can improve the certainty of authenticity and difficulty of counterfeiting as it gives more than one characteristic information to the artifact. In order to give two optical feature information (hue and emission intensity) into the ceramic products, we develop a new type of glass phosphor. This is a novel approach, since up-conversion phosphors with different color hue and emission intensity at each observation point on the material by optical excitation have never been reported. By welding a small amount of phosphor powder onto the surface of the ceramics, the certainty of authenticity and difficulty of counterfeiting would be enhanced than an existing method we proposed. Based on our experiment, we found appropriate blending ratio of two types of rare earth oxides for making glass phosphor with above-mentioned emission characteristics. These characteristics could be seen in other glass phosphor created by different base material glass with same blending ratio.

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Using Demercurated Lighting Phosphor and MSWI Scrubber Residues to Prepare High Performance Plastic Concrete

Materials Science Forum ◽

10.4028/www.scientific.net/msf.610-613.55 ◽

2009 ◽

Vol 610-613 ◽

pp. 55-60

Author(s):

Wu Jang Huang ◽

Wei Chu ◽

Ling Hui Hsieh ◽

Jian Guo Chen

Keyword(s):

Thermal Properties ◽

Epoxy Resin ◽

Solid Waste ◽

High Performance ◽

Waste Incineration ◽

Type I ◽

Phosphor Powder ◽

Force Microscopy ◽

Atomic Force ◽

Plastic Concrete

This study aimed to prepare a high performance plastic concrete made of epoxy resin and Portland type-I cement mixed with at least one inorganic solid waste of demercurated lighting phosphor powder or municipal solid waste incineration scrubber residue. The ratio between liquid epoxy resin and cement was 1:2; the scrubber residue and demercurated phosphor powder were added as modifiers for cement component in order to improve the strength and thermal properties of synthesized plastic concrete. The results indicate that, the addition of scrubber residue causes a decrease in both strength and thermal properties; whereas, the demercurated phosphor powder can replace 100% of the contents of cement without any significantly change in either strength or thermal properties. Atomic force microscopy and Raman spectroscopy were used to characterize the chemical structure of cured concrete and the results indicate that the surface softness increases with an increase in the mixed percentage of epoxy resin.

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Photoluminescence Properties Influenced by Calcining Condition and Doping Concentration of Nano-Sized ZnGa2O4: Cr3+

Materials Science Forum ◽

10.4028/www.scientific.net/msf.610-613.616 ◽

2009 ◽

Vol 610-613 ◽

pp. 616-620 ◽

Cited By ~ 3

Author(s):

Wei Wei Zhang ◽

Jun Ying Zhang ◽

Hui Wan ◽

Zi Yu Chen ◽

Tian Min Wang

Keyword(s):

Spinel Structure ◽

Doping Concentration ◽

Sol Gel ◽

Blue Shift ◽

Maximum Height ◽

Photoluminescence Properties ◽

Phosphor Powder ◽

Red Emission ◽

Intrinsic Excitation ◽

Gel Technique

Chromium-activated ZnGa2O4 nano-sized phosphor powder was prepared by the Sol-Gel technique using citric acid as chelator, and the microstructure and luminescent property were studied. The host ZnGa2O4 belongs to the spinel structure and the ZnGa2O4:Cr3+ phosphor powder exhibited bright red emission band. The excitation bands with peak of maximum height at about 250 nm, 410 nm and 560 nm were related to the charge transfer (CT) of Ga-O, 4A2-4T1 and 4A2-4T2 transitions of Cr3+, respectively. Different quenching concentrations of the CT state and intrinsic excitation were discovered originating from different energy transfer schemes. Meanwhile, with the increasing of the calcining temperature the PLE spectrum exhibited an obvious blue-shift which is attributed to the enhancement of the crystal field.

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