NANOSIZE POWDERS OF SILVER-DOPED SODIUM COBALT OXIDE SYNTHESIZED BY POLYMERIZED COMPLEX METHOD

2005 ◽  
Vol 04 (02) ◽  
pp. 237-244 ◽  
Author(s):  
TOSAWAT SEETAWAN ◽  
VITTAYA AMORNKITBAMRUNG ◽  
THANUSIT BURINPRAKHON ◽  
SANTI MAENSIRI

Nanosized powders used for the preparation of bulk Na1.5Co2O4 and Ag -doped Na1.5Co2O4 nanosized crystalline grains were synthesized by the polymerized complex (PC) method. X-ray diffraction analysis revealed that the nondoped and Ag -doped PC products were composed of Co3O4 and Na2CO3 phases. After a subsequent calcination at 800°C, the nondoped PC product was converted to powder of single phase γ- NaxCo2O4 , whereas the Ag -doped PC products remained as mixed phases of Co3O4 and Na2CO3 and Ag2O with a small trace of γ- NaxCo2O4 . SEM and TEM investigations showed that all the calcined products were powders of about 200–500 nm particle size.

2006 ◽  
Vol 301 ◽  
pp. 177-180 ◽  
Author(s):  
Yuichiro Kuroki ◽  
Tomoichiro Okamoto ◽  
Masasuke Takata

Copper aluminum disulfide (CuAlS2) powders were synthesized in an evacuated ampoule at elevated temperatures. X-ray diffraction analysis revealed that the powders heated at temperatures higher than 800oC were single-phase CuAlS2. In the cathodoluminescence (CL) spectra measured at room temperature, the powders heated at temperatures higher than 600oC exhibited a visible emission peak at approximately 1.8 eV and a distinct ultraviolet emission peak at 3.45 eV. The powder heated at 700oC showed the maximum intensity of ultraviolet emission which is considered to be associated with excitons.


2013 ◽  
Vol 566 ◽  
pp. 231-234 ◽  
Author(s):  
Takuya Tainaka ◽  
Takeyuki Kikuchi ◽  
Tatsuya Nakamura ◽  
Tohru Yamasaki ◽  
Makoto Nakanishi ◽  
...  

Synthesis of Sr3Zn2Fe24O41 Z-type ferrite was investigated. Precursors of ferrite were prepared by polymerizable complex method. Identification of formed phases in the obtained samples and determination of lattice parameters of Z-type ferrite were performed by powder X-ray diffraction (XRD). Single-phase of Sr3Zn2Fe24O41 Z-type ferrite was synthesized by heating at 1463 K for 5hours in air. M-H curve of prepared single-phase Sr3Zn2Fe24O41 Z-type ferrite was measured by using vibrating sample magnetometer (VSM). It was revealed that Sr3Zn2Fe24O41 Z-type ferrite has larger saturation magnetization (23.5 μB/formula unit) than that of Sr3Co2Fe24O41 (22.7 μB/formula unit) and shows characteristic two-step saturation of magnetization as well as Sr3Co2Fe24O41 Z-type ferrite.


2012 ◽  
Vol 508 ◽  
pp. 224-229 ◽  
Author(s):  
Takayuki Yanagida ◽  
Yoshisuke Futami ◽  
Noriaki Kawaguchi ◽  
Jan Pejchal ◽  
Yutaka Fujimoto ◽  
...  

ααΑαNd3+ 0.5% Doped Single Crystal LiCaAlF6 Scintillator Was Grown by the Micro-Pulling down (µ-PD) Method. Powder X-Ray Diffraction Analysis Was Done and the Grown Crystal Was a Single Phase LiCaAlF6. it Was Cut and Polished to the Physical Dimension of 1 × 2 × 7 mm3. in Transmittance Spectrum, Nd3+ 5d-4f Absorption Observed at 175 Nm and the Transmittance Became 80% at Wavelength Longer than 180 Nm. Excited by 160 Nm, Nd3+ 5d-4f Emission Appeared at 180 Nm. X-Ray Induced Radio-Luminescence Spectrum Showed the Similar Feature with the Photoluminescence One. when Coupled with PMT and Irradiated by 241Am α-Ray, the Absolute Light Yield Resulted 100 Ph/5.5 Mev α.


Author(s):  
А.В. Павленко ◽  
Д.В. Стрюков ◽  
Н.В. Тер-Оганесян

For the first time, thin films of NaNbO3 on a MgO(001) substrate, on which a SrRuO3 layer was previously deposited, were obtained by RF cathode sputtering in an oxygen atmosphere. According to x-ray diffraction analysis the films are single phase and single-crystalline. The lattice parameters in the tetragonal approximation for the NaNbO3 and SrRuO3 layers were: с(NaNbO3) = 0.3940(1) nm, a(NaNbO3) = 0.389(1) nm; с(SrRuO3) = 0.4004(1) nm, a(SrRuO3) = 0.392(3) nm. The unit cell deformation for NaNbO3 was ε33 = 0.007, ε11 = 0.002. Dielectric and piezoelectric measurements indicate that the films are in a ferroelectric state.


2012 ◽  
Vol 510-511 ◽  
pp. 201-205
Author(s):  
G. Asghar ◽  
S. Nasir ◽  
M.S. Awan ◽  
G.H. Tariq ◽  
M. Akram ◽  
...  

Phase purity, particle size and its distribution contributes a lot to the physical properties of M-type hexa-ferrites. These parameters are strongly influenced by the variation in synthesis parameters. In the present work, effect of synthesis parameters such as molar ratio (Fe/Sr) and volume rate of addition of precipitating agent on M-type hexa-ferrite (SrFe12O19) prepared by co-precipitation method have been investigated systematically. The molar ratio (Fe/Sr) in SrFe12O19was varied as 12, 11, 10, 09, and 08. X-ray diffraction analysis revealed that molar ratio does not affect the phase purity. X-ray diffraction analysis of the samples prepared with different volume rate of addition of precipitating agent indicated that phase purity and micro-structural properties of SrFe12O19are greatly influenced by the above synthesis parameter. High volume rate of addition of precipitating agent resulted in high phase purity, smaller particle size, and narrow particle size distribution.


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