SYNTHESIS AND CHARACTERIZATION OF Cd1-xZnxS:Cu CRYSTALS BY CO-PRECIPITATION METHOD

2001 ◽  
Vol 15 (17) ◽  
pp. 2387-2407 ◽  
Author(s):  
ABDUL NAYEEM ◽  
K. YADAIAH ◽  
G. VAJRALINGAM ◽  
P. MAHESH ◽  
M. NAGABHOOSHANAM
Keyword(s):  
Energy Gap ◽  
Precipitation Method ◽  
Optical Energy Gap ◽  
Chemical Homogeneity ◽  
X Ray ◽  
Cubic Structure ◽  
Co Precipitation ◽  
Controlled Precipitation

Copper doped Cd 1-x Zn x S compounds were prepared by controlled precipitation method with 0≤x≤1. The samples were characterized by X-ray, chemical analysis, optical absorption, and SEM studies. The X-ray studies have indicated that the compounds have polycrystalline nature with mixed Hexagonal and Cubic structure of CdS with x=0–0.6, the structure changed to a prominent cubic structure of ZnS with x>0.6. Optical studies have shown that the grain size increased with x varying from 0–0.2 and then it decreased. It was also observed that the optical energy gap decreased with x till x ⋍ 0.2, attained a minimum with x=0.2 and then it increased gradually. The values of E g obtained for CdS and ZnS were 2.21 eV and 2.53 eV. The chemical homogeneity of the samples was also observed from the EDAX and noted that the sulfur and copper contents remained almost the same, and the decrease in Cd and increase in Zn atoms occurred systematically. The results were explained on the basis of different phases formed and the role of copper impurity.

SYNTHESIS AND CHARACTERIZATION OF (CdSe)1-X(ZnS)x MIXED POLYCRYSTALLINE SEMICONDUCTORS BY CO-PRECIPITATION METHOD

2002 ◽  
Vol 16 (19) ◽  
pp. 2885-2899
Author(s):  
K. YADAIAH ◽  
ABDUL NAYEEM ◽  
M. SOMI REDDY ◽  
M. NAGABHOOSHANAM
Keyword(s):  
Energy Gap ◽  
Nitrogen Atmosphere ◽  
Hexagonal Structure ◽  
Ion Source ◽  
Precipitation Method ◽  
Scanning Electron Micrographs ◽  
Chemical Homogeneity ◽  
X Ray ◽  
Co Precipitation

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.

scholarly journals Crystallographic, Energy Gap, Photoluminescence and Photo-Catalytic Investigation of Cu Doped Cd0.9Zn0.1S Nanostructures by Co-Precipitation Method

2021 ◽  
Author(s):  
P. Raju ◽  
Joseph Prince Jesuraj ◽  
S. Muthukumaran
Keyword(s):  
Crystallite Size ◽  
Energy Gap ◽  
Wavelength Region ◽  
Lattice Parameter ◽  
Precipitation Method ◽  
Optical Absorbance ◽  
Stability Measurement ◽  
Cubic Structure ◽  
The Stability ◽  
Co Precipitation

Abstract The controlled synthesis of Cd0.9Zn0.1S, Cd0.89Zn0.1Cu0.01S and Cd0.87Zn0.1Cu0.03S nanostructures by simple chemical co-precipitation technique was reported. The XRD investigation confirmed the basic CdS cubic structure on Zn-doped CdS and also Zn, Cu dual doped CdS with no secondary/impurity related phases. No modification in cubic structure was detected during the addition of Zn/Cu into CdS. The reduction of crystallite size from 63 Å to 40 Å and the changes in lattice parameter confirmed the incorporation of Cu into Cd0.9Zn0.1S and generation of Cu related defects. The shift of absorption edge along upper wavelength region and elevated absorption intensity by Cu doping can be accredited to the collective consequence of quantization and the generation of defect associated states. The enhanced optical absorbance and the reduced energy gap recommended that Cd0.87Zn0.1Cu0.03S nanostructure is useful to enhance the efficiency of opto-electronic devices. The presence of Cd-S / Zn-Cd-S /Zn/Cu-Cd-S chemical bonding were confirmed by Fourier transform infrared investigation. The elevated green emissions by Cu incorporation was explained by decrease of crystallite size and creation of more defects. Zn, Cu dual doped CdS nanostructures are recognized as the possible and also efficient photo-catalyst for the removal dyes like methylene blue. The enhanced photo-catalytic behaviour of Zn, Cu dual doped CdS is the collective consequences of high density electron-hole pairs creation, enhanced absorbance in the visible wavelength, surface area enhancement, reduced energy gap and the formation of novel defect associated states. The stability measurement signified that Cu doped Cd0.9Zn0.1S exhibits superior dye removal ability and better stability even after 6 repetitive runs with limited photo-corrosion.

Synthesis and Characterization of Magnetite Particles by Co-Precipitation Method

2012 ◽  
Vol 512-515 ◽  
pp. 82-85 ◽  
Author(s):  
Ming Ya Li ◽  
Xu Dong Sui
Keyword(s):  
Spinel Structure ◽  
Bath Temperature ◽  
Precipitation Method ◽  
Scanning Electronic Microscopy ◽  
Electronic Microscopy ◽  
X Ray ◽  
Magnetite Particles ◽  
Co Precipitation ◽  
Different Diameters

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.

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
Keyword(s):  
Electron Probe ◽  
Precipitation Method ◽  
Yttrium Aluminium Garnet ◽  
Mineral Phase ◽  
X Ray ◽  
Yttrium Aluminium ◽  
Good Crystallinity ◽  
Co Precipitation ◽  
Scanning Electron

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.

scholarly journals Synthesis and Characterization of ZnS Nanoparticles Using Co-precipitation Method

2020 ◽  
pp. 26-33
Author(s):  
S. Mohanapriya ◽  
M. Vennila ◽  
S. Kowsalya
Keyword(s):  
Sodium Sulfide ◽  
Optical Characterization ◽  
Precipitation Method ◽  
Synthesis And Characterization ◽  
Precipitation Reaction ◽  
Zns Nanoparticles ◽  
X Ray ◽  
Homogeneous Chemical ◽  
Co Precipitation

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.

scholarly journals Band Gap Tailoring, Size Modulation and Photoluminescence Properties of Mn/Cu doped ZnS Nanostructures

2021 ◽  
Author(s):  
P.J. Binu ◽  
S. Muthukumaran
Keyword(s):  
Energy Gap ◽  
Effective Control ◽  
Photoluminescence Properties ◽  
X Ray Diffraction ◽  
Light Emitting ◽  
X Ray ◽  
Cubic Structure ◽  
Diffraction Patterns ◽  
Co Precipitation ◽  
Band Gap Tailoring

Abstract ZnS, Mn added ZnS (Zn0.97Mn0.03S) and Mn, Cu dual doped ZnS (Zn0.95Mn0.03Cu0.02S) QDs have been prepared using co-precipitation technique. The influence of Mn and Cu addition on the morphology, structure and photoluminescence properties of Mn/Cu incorporated ZnS have been examined. Cubic structure of the synthesized samples was confirmed by X-ray diffraction patterns. The incorporation of Cu in Zn-Mn-S lattice not only decreased the particle/grain size and also generates more defect based luminescent activation centres. The reduced energy gap by Mn addition was explained by sp-d exchange interaction and the elevated energy gap in Cu, Mn dual doped ZnS was expalined by Burstein–Moss effect. The tuning phenomenon of size as well as the energy gap in ZnS by Mn/Cu addition promote these materials for nano-electronic applications. FTIR spectra confirmed the presence of Mn/Cr-Zn-S bondings. The substitution of Mn /Cu provides an effective control over tuning of different emission colours which signifies their applications like light emitting diodes.

Synthesis and Characterization of Structure of Fe3O4@Graphene Oxide Nanocomposites

2016 ◽  
Vol 25 (6) ◽  
pp. 096369351602500 ◽  
Author(s):  
Ruimin Fu ◽  
Mingfu Zhu
Keyword(s):  
Graphene Oxide ◽  
Drug Carrier ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Ft Ir ◽  
Co Precipitation ◽  
Ft Ir Spectroscopy

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.

Study of Preparation, Characterization and Temperature-Programmed Reduction of NiO-ZnO Binary Materials

2013 ◽  
Vol 664 ◽  
pp. 515-520
Author(s):  
Chih Wei Tang ◽  
Jiunn Jer Hwang ◽  
Shie Hsiung Lin ◽  
Chin Chun Chung
Keyword(s):  
Weight Percent ◽  
Precipitation Method ◽  
Temperature Programmed Reduction ◽  
X Ray Diffraction ◽  
X Ray ◽  
Surface Areas ◽  
Temperature Programmed ◽  
Co Precipitation ◽  
Adsorption Desorption

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.

Role of Sm3+ Addition on Humidity Sensing of Nanocrystallite Mg-Cd Ferrites

2013 ◽  
Vol 645 ◽  
pp. 160-163 ◽  
Author(s):  
Gadkari B. Ashok ◽  
Shinde J. Tukaram ◽  
Vasambekar N. Pramod
Keyword(s):  
Recovery Time ◽  
Secondary Phase ◽  
Precipitation Method ◽  
Response And Recovery ◽  
Low Humidity ◽  
Ft Ir ◽  
Co Precipitation ◽  
Humidity Range

Nanocrystallite powders of 5 wt% Sm3+ added Mg-Cd ferrite samples were prepared by oxalate co-precipitation method. XRD, SEM and FT-IR techniques were used for characterization of the samples. The XRD reveals cubic spinel nature with secondary phase (SmFeO3). The crystallite size lies in the range of 28.69 to 32.66 nm. All the Sm3+ ions added samples are humidity sensitive at low humidity range 40 to70 %RH. The electrical resistivity of Sm3+ ions added samples decreased by four orders of magnitude, when %RH increased from 40%RH to 90 %RH. The response and recovery time of all the samples are 160-290 sec. The shorter response time was observed for Sm3+ added Cd ferrite sensor.

scholarly journals A study of the characterization of CdS/PMMA nanocomposite thin film

2019 ◽  
Vol 14 (29) ◽  
pp. 191-197
Author(s):  
Awras H. Ajil
Keyword(s):  
Energy Gap ◽  
Spray Pyrolysis Method ◽  
Chemical Spray Pyrolysis ◽  
X Ray Diffraction ◽  
Optical Energy Gap ◽  
Host Matrix ◽  
Chemical Spray ◽  
Before And After ◽  
Co Precipitation

Nanocomposites of polymer material based on CdS as fillermaterial and poly methyl methacrylate (PMMA) as host matrix havebeen fabricated by chemical spray pyrolysis method on glasssubstrate. CdS particles synthesized by co-precipitation route usingcadimium chloride and thioacetamide as starting materials andammonium hydroxide as precipitating agent. The structure isexamined by X-ray diffraction (XRD), the resultant film hasamorphous structure. The optical energy gap is found to be (4.5,4.06) eV before and after CdS addition, respectively. Electricalactivation energy for CdS/PMMA has two regions with values of0.079 and 0.433 eV.

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