scholarly journals Luminescence efficiency of cerium-doped yttrium aluminum garnet ceramics formed by radiation assisted synthesis

2021 ◽  
Vol 6 (6 (114)) ◽  
Author(s):  
Gulnur Alpyssova ◽  
Victor Lisitsyn ◽  
Mikhail Golkovski ◽  
Dossymkhan Mussakhanov ◽  
Zhakyp Karipbayev ◽  
...  
Keyword(s):  
Yttrium Aluminum Garnet ◽  
Structural Phase ◽  
Spectral Characteristics ◽  
Statistical Processing ◽  
Luminescent Properties ◽  
High Rate ◽  
Kinetic Properties ◽  
Radiation Synthesis ◽  
Luminescence Efficiency ◽  
Yttrium Aluminum

The variety of applications of yttrium-aluminum garnet (YAG)-based luminescent materials and the morphology necessary for these purposes required the development of many technologies for their synthesis. All synthesis technologies used are complex. The structural phase of yttrium-aluminum garnet is formed with any technology, at temperatures exceeding 1,500 °C. The starting materials for the synthesis are metal oxides of aluminum, yttrium and other oxides for activation and modification. It seems possible to use hard radiation to form a new phase. Radiation synthesis of ceramics is realized in less than 1 s, without the use of any additives and influences. The synthesis was carried out at the electron accelerator of the Institute of Nuclear Physics (Novosibirsk). In this work, we studied the spectral-kinetic and quantitative characteristics of luminescence for the first time obtained by the method of radiation synthesis of ceramic samples of yttrium-aluminum garnet doped with cerium with statistical processing of their values. The dependences of the reproducibility of the spectral characteristics of the luminescence of the samples on the preliminary preparation of the charge for synthesis have been investigated. Several cycles of luminophore brightness studies have been performed. It is shown that the obtained ceramics based on yttrium-aluminum garnet doped with cerium possesses the required spectral-kinetic properties, and the efficiency of conversion of the chip radiation into luminescence is achieved, which is comparable to that available in commercial phosphors. The maximum measured values of the position of the bands are from 553.5 to 559.6 nm. Brightness values range from 4,720 to 1,960 cd/m2. It was found that the main reason for the scatter in the characteristics of the luminescent properties of ceramics of yttrium-aluminum garnet, activated by cerium obtained by radiation assisted synthesis is the high rate of synthesis and, especially, the high rate of cooling of the samples.

Spectral characteristics of neodymium-activated yttrium aluminum garnet in the ultraviolet and visible ranges

1982 ◽  
Vol 12 (6) ◽  
pp. 731-736 ◽  
Author(s):  
Khachik S Bagdasarov ◽  
I S Volodina ◽  
A I Kolomiĭtsev ◽  
M L Meĭl'man ◽  
A G Smagin
Keyword(s):  
Yttrium Aluminum Garnet ◽  
Spectral Characteristics ◽  
Yttrium Aluminum

Effect of the europium doping on the structural and luminescent properties of yttrium aluminum garnet

2013 ◽  
Vol 178 (4) ◽  
pp. 248-253 ◽  
Author(s):  
L.E. Muresan ◽  
E.J. Popovici ◽  
I. Perhaita ◽  
E. Indrea ◽  
T.D. Silipas
Keyword(s):  
Yttrium Aluminum Garnet ◽  
Luminescent Properties ◽  
Europium Doping ◽  
Yttrium Aluminum

scholarly journals Minimally Invasive Management of Iatrogenic Ureteral Injuries with Ureteroscope Facilitated by Holmium Yttrium-Aluminum-Garnet Laser

2014 ◽  
Vol 2014 ◽  
pp. 1-4 ◽  
Author(s):  
Zongyao Hao ◽  
Li Zhang ◽  
Jun Zhou ◽  
Xiansheng Zhang ◽  
Haoqiang Shi ◽  
...  
Keyword(s):  
Yttrium Aluminum Garnet ◽  
High Rate ◽  
Surgical Approaches ◽  
Ho:Yag Laser ◽  
Minimal Scarring ◽  
Novel Approach ◽  
Ureteral Injuries ◽  
Yttrium Aluminum ◽  
Invasive Management

The ureter is vulnerable during general, gynecologic, and urologic surgeries. The traditional open surgical approaches to treating the iatrogenic ureteral injuries have shown several disadvantages such as relatively high rate of severe complications. Although the applications of endourological techniques for management of lower ureteral strictures have been routinely introduced over the last 10 years, most of the different modalities were based on the utilization of hydrophilic instruments that can facilitate the traversal of strictures surrounded by the sutures with gradually increasing force. Interestingly, we have revealed the Ho:YAG laser as the outstanding auxiliary approach to incising the sutures during the ureteroscopy for its well-controlled penetration depth, minimal scarring, and precise cutting. As far as we know, the combined utilization of Ho:YAG laser to incise the sutures responsible for the strictures and double J ureteral stent for drainage has not been extensively reported. Normal ureters of the patients managed by this novel approach were shown by the follow-up 3-4 months later, which demonstrated that the available technique was promising to effectively treat the iatrogenic ureteral injuries.

scholarly journals LUMINESCENCE OF YAG:Ce DOPED WITH SILVER NANOPARTICLES

2021 ◽  
pp. 220-227
Author(s):  
Александр Александрович Кравцов ◽  
Ирина Сергеевна Чикулина ◽  
Дмитрий Сергеевич Вакалов ◽  
Олег Михайлович Чапура ◽  
Святослав Олегович Крандиевский ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Yttrium Aluminum Garnet ◽  
Chemical Reduction ◽  
Spectral Characteristics ◽  
Ceramic Powder ◽  
Precursor Powder ◽  
Precipitation Method ◽  
Photoluminescence Intensity ◽  
Two Stage ◽  
Yttrium Aluminum

В работе впервые было исследовано влияние наночастиц серебра на люминесценцию иттрий-алюминиевого граната, легированного церием. С помощью метода химического восстановления был синтезирован золь с размером наночастиц серебра ≈100 нм. Керамический порошок люминофора иттрий-алюминиевого граната, легированного церием, был получен методом двухстадийного осаждения в уротропин. Золь наночастиц серебра в концентрациях от 0,125 до 0,1 мл вводили в порошок-прекурсор перед прокаливанием. Было показано, что при данном способе введения наночастиц серебра интенсивность фотолюминесценции возрастала по сравнению с эталоном. Оптимальной концентрацией в рамках исследования являлась концентрация 0,25 мл. При данной концентрации увеличение интенсивности фотолюминесценции на длине волны 540 нм составило порядка 10%. Проведенные исследования показали, что наночастицы серебра могут с успехом применяться для увеличения яркости люминофора иттрий-алюминиевого граната, легированного церием, без искажения и ухудшения спектральных характеристик. This work was the first to study the effect of silver nanoparticles on the luminescence of cerium doped yttrium-aluminum garnet. A sol with the size of silver nanoparticles of ≈100 nm was synthesized using the method of chemical reduction. Phosphor ceramic powder of the yttrium-aluminum garnet doped with cerium was obtained by the two-stage precipitation method. The silver nanoparticles sol was introduced into the precursor powder before calcination in concentrations from 0,125 to 0,1 ml. It was shown that the photoluminescence intensity increased in comparison with the reference when we used this method of introducing silver nanoparticles. The optimal concentration within the study was 0,25 ml. At this concentration, the increase in the photoluminescence intensity at a wavelength of 540 nm was about 10 %. Studies have shown that silver nanoparticles can be successfully used to increase the brightness of the phosphor of the yttrium-aluminum garnet doped with cerium without distortion and deterioration of spectral characteristics.

Synthesis of Green-Emitting Phosphor Y3Al5O12: Tb, Ce, Gd by Sol-Gel Method

2007 ◽  
Vol 336-338 ◽  
pp. 610-612
Author(s):  
Li Min Dong ◽  
Zhi Dong Han ◽  
Ze Wu ◽  
Xian You Zhang
Keyword(s):  
Yttrium Aluminum Garnet ◽  
Sol Gel ◽  
Spherical Shape ◽  
High Irradiance ◽  
Gel Method ◽  
Sol Gel Method ◽  
Luminescence Efficiency ◽  
Yttrium Aluminum ◽  
Fine Size ◽  
Sintering Condition

Green-emitting Y3Al5O12: Tb phosphor materials have been widely studied because of their high luminescence efficiency and stability under the conditions of high irradiance with an electron beam. In this paper, Green-emitting phosphor of yttrium aluminum garnet (Y3Al5O12 or YAG) doped with Tb3+, Ce3+ and Gd3+ was synthesized by sol-gel method. By means of TG/DSC, XRD, and photoluminescence (PL) performance, the sintering condition and its influence on the powder’s emitting performance were studied. The experimental results showed that, Y2.8Tb0.12 Ce0.08-x GdxAl5O12 synthesized by sol-gel method was a kind of phosphor of good performance. When the value of x was set at 0.04, the best emitting performance was obtained. The Y3Al5O12: Tb, Ce, Gd particles had fine size, spherical shape, filled morphology, high crystallinity, and good brightness.

Inorganic Composites Luminophors in Lithium-Borate Glasses with Rare-Earth Elements for White-Emitting Diodes

2021 ◽  
Vol 410 ◽  
pp. 764-769
Author(s):  
Anna V. Tepikina ◽  
Svetlana G. Vlasova
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Composite System ◽  
Yttrium Aluminum Garnet ◽  
Spectral Characteristics ◽  
Lithium Borate ◽  
Radiation Spectra ◽  
Inorganic Composites ◽  
Yttrium Aluminum ◽  
Lithium Borate Glass

The paper describes the synthesis of novel luminescent composite system, based on lithium-borate glass matrix with addition of rare-earth elements and yttrium-aluminum garnet finely divided powder. The new chemical composition of glass has been selected, composite’s fabrication technology was developed, the temperature conditions of glass and luminophore sintering as well. The spectral characteristics of the obtained luminescent composites are measured, and chromaticity diagrams are considered. The radiation spectra showed a maximum of about 560 nm, the maximum spectral intensity of the radiation is about 90 μw/cm2/nm. Powerful energy saving source of white light was produced.

Yag Single Crystals for Scintillators of Stem

1990 ◽  
Vol 48 (1) ◽  
pp. 166-167
Author(s):  
M. Hibino ◽  
K. Irie ◽  
R. Autrata ◽  
P. schauer
Keyword(s):  
Single Crystals ◽  
Yttrium Aluminum Garnet ◽  
Light Guide ◽  
Detection System ◽  
Polished Surface ◽  
Detective Quantum Efficiency ◽  
Backscattered Electrons ◽  
Electron Detection ◽  
Yttrium Aluminum ◽  
Phosphor Screens

Although powdered phosphor screens are usually used for scintillators of STEM, it has been found that the phosphor screen of appropriate thickness should be used depending on the accelerating voltage, in order to keep high detective quantum efficiency. 1 It has been also found that the variation in sensitivity, due to granularity of phosphor screens, makes the measurement of fine electron probe difficult and that the sensitivity reduces with electron irradiation specially at high voltages.In order to find out a preferable scintillator for STEM, single crystals of YAG (yttrium aluminum garnet), which are used for detecting secondary and backscattered electrons in SEM were investigated and compared with powdered phosphor screens, at the accelerating voltages of 100kV and 1 MV. A conventional electron detection system, consisting of scintillator, light guide and PMT (Hamamatsu Photonics R268) was used for measurements. Scintillators used are YAG single crystals of 1.0 to 3.2mm thicknesses (with surfaces matted for good interface to the light guide) and of 0.8mm thickness (with polished surface), and powdered P-46 phosphor screens of 0.07mm and 1.0mm thicknesses for 100kV and 1MV, respectively. Surfaces on electron-incidence side of all scintillators are coated with reflecting layers.

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