Study on Preparation and Characterization of YAG Ceramic Synthesized by Co-Precipitation

2011 ◽  
Vol 284-286 ◽  
pp. 1317-1320
Author(s):  
Quan Shui Chen ◽  
Xiao Dong Liu ◽  
Guang Yuan Ren ◽  
Pan Yi Liang ◽  
Hui Ma

Yttrium Aluminium Garnet (YAG) has a extensive applications in many fields because of its excellent properties. In this study the products synthesized by co-precipitation method is regular, and the reaction is complete, the YAG ceramic obtained is white, its density is 2.42g/cm3 and shrinkage is 7.78%. The YAG ceramic tablets were investigated by Field emission scanning electron microscopy (FE-SEM), Electron probe microanalysis (EPMA) and X-ray diffractometer (XRD). The results show that the structure of YAG ceramic is loose with spherical grain size of 0.2-0.3μm. The main mineral phase of YAG ceramic is composed of polycrystalline Al5Y3O12 with good crystallinity, and containing very small amount of unreacted alumina and other impurities.

2021 ◽  
Vol 234 ◽  
pp. 00106
Author(s):  
Houda Labjar ◽  
Hassan Chaair

The synthesis of apatite silicated Ca10(PO4)6-x(SiO4)x(OH)2-x (SiHA) with 0≤x≤2 was investigated using a wet precipitation method followed by heat treatment using calcium carbonate CaCO3 and phosphoric acid H3PO4 and silicon tetraacetate SiC8H20O4 (TEOS) in medium of water ethanol, with three different silicate concentrations. After drying, the samples are ground and then characterized by different analytical techniques like X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR) and Scanning electron Microscopy (SEM) and chemical analysis.


2013 ◽  
Vol 838-841 ◽  
pp. 2306-2309
Author(s):  
Guang Hua Wang ◽  
Kun Chen ◽  
Wen Bing Li ◽  
Dong Wan ◽  
Qin Hu ◽  
...  

Magnetic modified organobentonite (Fe3O4/CTAB–Bent) was synthesized by chemical co-precipitation method in which CTAB–Bent was firstly achieved via ion–exchange.The composite materials have been characterized by powder X–ray diffraction (XRD), Fourier transform infrared spectroscopy (FT–IR) and Scanning electron microscopy (SEM) . The results revealed that basal spacing of bentonite was increased through organic modification and the Fe3O4 particles synthesized which covering the surfaces of bentonite .Compared with natural bentonite, the adsorption capacity of Fe3O4/CTAB–Bent for Orange II was greatly enhanced and can be easily separated from the reaction medium by an external magnetic field after the treatment.


2017 ◽  
Vol 17 (01n02) ◽  
pp. 1760015 ◽  
Author(s):  
Anju Anna Jacob ◽  
L. Balakrishnan ◽  
S. R. Meher ◽  
K. Shambavi ◽  
Z. C. Alex

Zinc oxide (ZnO) is a wide bandgap semiconductor with excellent photoresponse in ultra-violet (UV) regime. Tuning the bandgap of ZnO by alloying with cadmium can shift its absorption cutoff wavelength from UV to visible (Vis) region. Our work aims at synthesis of Zn[Formula: see text]CdxO nanoparticles by co-precipitation method for the fabrication of photodetector. The properties of nanoparticles were analyzed using X-ray diffractometer, UV–Vis spectrometer, scanning electron microscope and energy dispersive spectrometer. The incorporation of cadmium without altering the wurtzite structure resulted in the red shift in the absorption edge of ZnO. Further, the photoresponse characteristics of Zn[Formula: see text]CdxO nanopowders were investigated by fabricating photodetectors. It has been found that with Cd alloying the photosensitivity was increased in the UVA-violet as well in the blue region.


2012 ◽  
Vol 512-515 ◽  
pp. 82-85 ◽  
Author(s):  
Ming Ya Li ◽  
Xu Dong Sui

The Fe3O4 nanoparticles with different diameters were prepared by co-precipitation method in this paper. Magnetite particles with different diameters were fabricated by changing the concentration of the reactants and the reaction temperature. The influences of process parameters on the microstructure and properties of magnetic nanopariticles were studied. The obtained samples were characterized by X-ray powder diffraction and scanning electronic microscopy. Besides, vibrating sample magnetmeter was used to characterize the magnetic properties. The results show that all the as-synthesized magnetite nanoparticles are well crystallized and can be indexed into spinel structure. The appearance and magnetism of the particles with different diameter are different from each other. When the ratio of Fe3+ and Fe2+ is 2:1 or 4:3, the product was pure and good crystalline. Furthermore, higher saturation magnetization was obtained in a higher bath temperature.


Author(s):  
S. Mohanapriya ◽  
M. Vennila ◽  
S. Kowsalya

ZnS nanoparticles were prepared from homogeneous chemical co-precipitation reaction by using zinc acetate, sodium sulfide [Na2S] and Poly Vinyl Polypyrrolidone [PVP]. The basic, morphological, and optical properties of the synthesized nanoparticles were characterized using Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), Energy Dispersive X-ray Analysis (EDX) and Ultraviolet-Visible (UV-Vis) absorption. The structural and optical characterization of the samples observed by SEM, FTIR, EDX and UV-Vis spectrometer showed that ZnS nanoparticles were formed.


2016 ◽  
Vol 25 (6) ◽  
pp. 096369351602500 ◽  
Author(s):  
Ruimin Fu ◽  
Mingfu Zhu

Nowadays, the hummers method for preparation of graphene oxide (GO) was improved. The grapheme oxide @ Fe3O4 magnetic nanocomposites were synthesized by co-precipitation method. After analysing the morphology and structure of obtained nanocomposites by X-ray diffraction (XRD), transmission electron microscope (TEM) and Fourier transform infrared (FT-IR) spectroscopy, the result was shown as follows. The particle size of Fe3O4 in nanocomposites is 30 nm. Many functional groups are found in grapheme oxide, and such groups could be used to bind with the drug. In the test for magnetic properties, the nanocomposites gathered rapidly in the vicinity of the permanent magnet. The nanocomposites, with high superparamagnetism, can be used in the following applications: drug targeting transports, drug carrier, and diagnosis assistant system.


2011 ◽  
Vol 308-310 ◽  
pp. 2180-2186
Author(s):  
Hui Yang ◽  
Fei Fei Huang ◽  
Ke Wei Xu

In order to find a simple way to prepare oriental HA, only by controlling the preparation conditions, a co-precipitation method was used to prepare an oriented HA. The influences of temperature and aging on its directional growth were investigated kinetically and thermodynamically. The chemical composition was characterized by X-Ray diffraction and Fourier transform infrared. The morphologies were observed by scanning electron microscopy (SEM). The oriented parameters of HA (c/a) were calculated by Scherrer equation. The results show that the temperature rise in the process of synthesis, aging or calcining inhibited the growth of HA crystal in the direction of c-axis. Aging for 24 h benefited the growth along c-axis, whereas aging for 36 h was in favor of the decreasing of the c/a value. The supernatant-replacement during aging exerted the same effect on the growth with the rising of temperature. The SEM analysis result shows that the morphology of the produced HA particles looked like a uniform needle shape and had a good dispersion.


2016 ◽  
Vol 16 (4) ◽  
pp. 3534-3541
Author(s):  
Yanqiu Zhang ◽  
Baojiu Chen ◽  
Xiangping Li ◽  
Jiashi Sun ◽  
Jinsu Zhang ◽  
...  

Nanosized Gd6WO12 phosphors containing various Er3+ concentrations and fixed Yb3+ concentration were synthesized by a co-precipitation method. The crystal structure and microscopic morphology of the obtained nanophosphors were characterized by means of X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM). Two-photon processes for both the green and red upconversion (UC) emissions were confirmed by analyzing the dependence of UC intensities on 980 nm laser working current. UC emission intensity changing with temperature displays different trends for the samples with different Er3+ concentrations. The experimental results indicated that thermal quenching behavior of UC luminescence could not be simply explained by crossover mechanism. The enhancement for green UC emission in the sample with higher Er3+ concentration was discussed. Finally, the Er3+ concentration dependence of UC luminescence was experimentally observed, and its mechanisms were analyzed.


2013 ◽  
Vol 664 ◽  
pp. 515-520
Author(s):  
Chih Wei Tang ◽  
Jiunn Jer Hwang ◽  
Shie Hsiung Lin ◽  
Chin Chun Chung

The NiO-ZnO binary materials had been prepared by co-precipitation method. The weight percent of nickel of NiO-ZnO materials were 5, 10 and 20; they were pretreated under air at temperature of 300, 500 and 700°C, respectively. The characterization of NiO-ZnO materials were the thermal gravity analysis(TGA), X-ray diffraction(XRD), N2 adsorption-desorption at 77K, scaning electron microscope(SEM) and temperature-programmed reduction(TPR). The results revealed that surface areas of NiO-ZnO materials order from large to small were 20NiZn(OH)x(66 m2·g-1) > 10NiZn(OH)x(34 m2·g-1) > 5NiZn(OH)x(9 m2·g-1) after being calcined at the temperature of 500°C. Further, NiO-ZnO materials had two main reductive peaks at 390-415°C and 560-657°C, respectively. In all NiO-ZnO materials, 20NiZn(OH)x-C500 material had the highest surface area and the best interaction between NiO and ZnO.


2002 ◽  
Vol 16 (19) ◽  
pp. 2885-2899
Author(s):  
K. YADAIAH ◽  
ABDUL NAYEEM ◽  
M. SOMI REDDY ◽  
M. NAGABHOOSHANAM

The polycrystalline (CdSe)1-x (ZnS)x semiconductor powder with (0 ≤ x ≤ 1) has been prepared by controlled co-precipitation method from an alkaline medium using thiourea as a sulphide ion source. Pellets are made out of these powders under 10 tonnes/sq.cm pressure and are sintered at 800°C for 2 hours in nitrogen atmosphere. X-ray studies have indicated that the compounds are polycrystalline in nature with mixed hexagonal structure of CdSe with x = 0-0.3 and cubic structure of ZnS with x = 1. The chemical homogeneity of the samples was observed from the EDAX and also noted that the atomic contents present were as per the constituents taken in the solution. Lattice parameters (a and c) of all the compounds are determined from the X-ray data and are found to decrease with the increase in ZnS content. It is also observed that the grain size decreases with the increase in x from 0-0.6 and later it remained almost the same till x reaches 0.9. Optical studies indicated that the energy gap was as high as 5.2 eV and remained almost same throughout the composition range x = 0-1. Scanning electron micrographs have shown platelet like structure in CdSe and mixed compounds where as a mixed Cubic and Hexagonal structure in ZnS. The results are explained based on different phases present in the compounds.


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