The Various Concentration Effected on Crystallite Size of Calcium Carbonate

2016 ◽  
Vol 675-676 ◽  
pp. 667-670
Author(s):  
Sunti Phewphong ◽  
Kanokwan Najai ◽  
Tosawat Seetawan

The calcium carbonate was extracted from Pomacea Canaliculata Lamarck (Cherry shell) by using the hydrothermal method. Cherry shell was washed and crushed by DI water and mortar. The powder size was analyzed by particle (aperture Size 63 μm), added x HCl (x = 2, 3, 4) and y Na2CO3 (y = 1, 1.5, 2) mixed with fine powder from Cherry shell. The mixed power was filtered annealed by autoclave at controlled temperature at 333 K for 20 h. The crystal structure was characterized by X−ray diffraction method. The phase transformation of CaCO3 was analyzed by Fourier transform infrared spectroscopy (FTIR). The morphology of Cherry shell and CaCO3 powders were observed by using scanning electron microscope (SEM). It was found that the extracted CaCO3 shows single phase of CaCO3 crystal structure. Smallest crystallite size was found about of 0.54 μm.

1951 ◽  
Vol 22 (5) ◽  
pp. 665-672 ◽  
Author(s):  
Alfred J. Reis ◽  
Jerome J. Slade ◽  
Sigmund Weissmann

2014 ◽  
Vol 70 (a1) ◽  
pp. C1560-C1560
Author(s):  
Fumiko Kimura ◽  
Wataru Oshima ◽  
Hiroko Matsumoto ◽  
Hidehiro Uekusa ◽  
Kazuaki Aburaya ◽  
...  

In pharmaceutical sciences, the crystal structure is of primary importance because it influences drug efficacy. Due to difficulties of growing a large single crystal suitable for the single crystal X-ray diffraction analysis, powder diffraction method is widely used. In powder method, two-dimensional diffraction information is projected onto one dimension, which impairs the accuracy of the resulting crystal structure. To overcome this problem, we recently proposed a novel method of fabricating a magnetically oriented microcrystal array (MOMA), a composite in which microcrystals are aligned three-dimensionally in a polymer matrix. The X-ray diffraction of the MOMA is equivalent to that of the corresponding large single crystal, enabling the determination of the crystal lattice parameters and crystal structure of the embedded microcrytals.[1-3] Because we make use of the diamagnetic anisotropy of crystal, those crystals that exhibit small magnetic anisotropy do not take sufficient three-dimensional alignment. However, even for these crystals that only align uniaxially, the determination of the crystal lattice parameters can be easily made compared with the determination by powder diffraction pattern. Once these parameters are determined, crystal structure can be determined by X-ray powder diffraction method. In this paper, we demonstrate possibility of the MOMA method to assist the structure analysis through X-ray powder and single crystal diffraction methods. We applied the MOMA method to various microcrystalline powders including L-alanine, 1,3,5-triphenyl benzene, and cellobiose. The obtained MOMAs exhibited well-resolved diffraction spots, and we succeeded in determination of the crystal lattice parameters and crystal structure analysis.


2013 ◽  
Vol 802 ◽  
pp. 119-123
Author(s):  
Supamas Wirunchit ◽  
Rangson Muanghlua ◽  
Supamas Wirunchit ◽  
Wanwilai Vittayakorn ◽  
Naratip Vittayakorn

Nanocrystalline barium zirconium titanate, BaZr0.4Ti0.6O3, was synthesized successfully via the sonochemical process. The effects of reaction time on the precipitation of Ba(Zr,Ti)O3 particles were investigated briefly. The crystal structure as well as molecular vibrations and morphology were investigated. X-ray diffraction indicated that the powders exhibited a single phase perovskite structure, without the presence of pyrochlore or unwanted phases at the reaction time of 60 min. Nanocrystals were formed before being oriented and aggregated into large particles in aqueous solution under ultrasonic irradiation. A scanning electron microscopy (SEM) photograph showed the BZT powder as spherical in shape with uniform nanosized features.


2014 ◽  
Vol 979 ◽  
pp. 200-203 ◽  
Author(s):  
Pannipa Chaya ◽  
Tula Jutarosaga ◽  
Wandee Onreabroy

The strontium hexaferrite (SrFe12O19) and Co-substituted strontium hexaferrite (SrCoFe11O19) were prepared by ceramic method. The milled mixture of Fe2O3, SrCO3 and CoO powders were calcined at 1100°C and pellets sintered at 1300°C in air. The crystal structure, morphology and magnetic properties of samples have been investigated by X-ray diffraction (XRD), scanning electron microscope (SEM) and vibrating sample magnetometer (VSM), respectively. The crystal structure of SrFe12O19 was hexaferrite with the crystallite size and the lattice constants a and c of 59.6 nm, 5.8 Å, and 23.0 Å, respectively. Also, the crystal structure of SrCoFe11O19 was hexaferrite with the crystallite size and the lattice constants a and c of 63.7 nm, 5.9 Å and 23.0 Å, respectively. The morphology of obtained samples changed from hexagonal rods to discs shape and grain sizes increased with the increase of doped Co in SrFe12O19. SrFe12O19 with the coercive force (Hc) of 2,133 Oe was classified as hard ferrite magnetic. While, Co-substituted strontium hexaferrite (SrCoFe11O19) was soft ferrite magnetic with coercive force of 64 Oe. Results indicated that magnetic properties of samples such as hard ferrite magnetic and soft ferrite magnetic showed great dependence on the cobalt additive in strontium.


2013 ◽  
Vol 802 ◽  
pp. 227-231
Author(s):  
Panida Pilasuta ◽  
Pennapa Muthitamongkol ◽  
Chanchana Thanachayanont ◽  
Tosawat Seetawan

Crystal structure of Zn0.96Al0.02Ga0.02O was analyzed by X-Ray diffraction (XRD) technique and the microstructure was observed by scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The XRD results showed single phase and hexagonal structure a = b = 3.24982 Å, and c = 5.20661 Å. The SEM and TEM results showed the grain size of material arrangement changed after sintering and TEM diffraction pattern confirmed hexagonal crystal structure of Zn0.96Al0.02Ga0.02O after sintering.


1990 ◽  
Vol 04 (12) ◽  
pp. 791-794 ◽  
Author(s):  
YANG JI-LIAN ◽  
YE CHUN-TANG ◽  
ZHANG BAI-SHENG ◽  
LI JI-ZHOU ◽  
KANG JIAN ◽  
...  

The polycrystalline sample of (Bi–Pb)2Sr2Ca2Cu3O10 with Tc=107 K was prepared. The X-ray diffraction proved that the sample is single phase. The crystal structure study on the sample has been carried out by neutron diffraction. The result shows that its structure is tetragonal body-centre structure with space group of I4/mmm, containing a few oxygen atoms at 4e site in Bi–Pb layers.


1988 ◽  
Vol 3 (1) ◽  
pp. 19-22 ◽  
Author(s):  
J. Schlichter ◽  
I. Mayer ◽  
S. Sarig ◽  
N. Garti

AbstractThe effect of solid emulsifiers, added at the level of 10%, on the lattice parameters of tristearin and trilaurin, has been studied by powder X-ray diffraction method. The presence of sorbitan monostearate and glycerol-l-stearate affects slightly the lattice constant a in tristearin; on the other hand, although sorbitan monostearate causes an increase in a of trilaurin, glycerol-l-stearate does not. The presence of sorbitan monolaurate and glycerol-l-laurate affect a of trilaurin similarly to the long chain emulsifiers.A correlation between the effect on a and the increase in melting point has been found.The presence of the emulsifier does not alter drastically the lattice dimensions of the fat. The slight dissimilarity in crystal structure between tristearin and trilaurin is confirmed by the diverse effects of the emulsifiers on the internal structure of the fat.


2014 ◽  
Vol 602-603 ◽  
pp. 947-950
Author(s):  
Zhen Wang ◽  
Hai Yan Chen ◽  
Lin Qiang Gao ◽  
Xin Zou

BiFeO3 nanoparticles were successfully synthesized by a hydrothermal method by a mineralizer (KNO3). Structural characterization was performed by thermal analysis, powder X-ray diffraction (XRD) and scanning electron microscopy (TEM).The results showed that the products were perovskite structure BiFeO3 powders. Optimal conditions for the synthesis of single-phase BiFeO3 ceramics were obtained.


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