Hydrothermal Synthesis and Structural Characterization of Orthorhombic LiMnO2 with Low Stacking Faults

2015 ◽  
Vol 1120-1121 ◽  
pp. 174-178
Author(s):  
Li Zhu Zhao ◽  
G. Chen

LiMnO2 are synthesized by hydrothermal technique by using Mn(CH3COO)2.4H2O and MnO2 with the same mole ratio which are dissolved in aqueous solution with different concentration LiOH. Structural characterization based on X-ray diffraction and Raman spectroscopy reveals that LiMnO2 is in a well-order orthorhombic structure with lower stacking faults compared to the LiMnO2 prepared by other techniques. Experimental results show that the concentration of lithium hydroxide in aqueous solution affect the quality of LiMnO2.

Clay Minerals ◽  
1994 ◽  
Vol 29 (1) ◽  
pp. 33-38 ◽  
Author(s):  
A. Plançon ◽  
V. A. Drits

AbstractAn expert system has been designed for the structural characterization of disordered phyllosilicates as well as the mixed-layer minerals and the minerals containing stacking faults or isomorphic substitutions. X-ray diffraction being the simplest tool for structural characterization, the expert system uses such data but can account for data provided by any characterization technique (infrared spectroscopy, EXAFS, etc.). The expert system aims to summarize in a unique set the different approaches of the structural characterization using diagrams or tables which have been proposed, avoiding the requirement of the knowledge of their application field and excluding calculations. It runs in an interactive way, to mimic the way a human expert would draw its conclusions.


1997 ◽  
Vol 07 (03n04) ◽  
pp. 265-275
Author(s):  
R. Q. Zhang ◽  
S. Yamamoto ◽  
Z. N. Dai ◽  
K. Narumi ◽  
A. Miyashita ◽  
...  

Natural FeTiO 3 (illuminate) and synthesized FeTiO 3, single crystals were characterized by Rutherford backscattering spectroscopy combined with channeling technique and particle-induced x-ray emission (RBS-C and PIXE). The results obtained by the ion beam analysis were supplemented by the x-ray diffraction analysis to identify the crystallographic phase. Oriented single crystals of synthesized FeTiO 3 were grown under the pressure control of CO 2 and H 2 mixture gas using a single-crystal floating zone technique. The crystal quality of synthesized FeTiO 3 single crystals could be improved by the thermal treatment but the exact pressure control is needed to avoid the precipitation of Fe 2 O 3 even during the annealing procedure. Natural FeTiO 3 contains several kinds of impurities such as Mn , Mg , Na and Si . The synthesized samples contain Al , Si and Na which are around 100 ppm level as impurities. The PBS-C results of the natural sample imply that Mn impurities occupy the Fe sublattice in FeTiO 3 or in mixed phase between ilmenite and hematite.


1997 ◽  
Vol 306 (2) ◽  
pp. 198-204 ◽  
Author(s):  
A.A. Darhuber ◽  
J. Stangl ◽  
V. Holy ◽  
G. Bauer ◽  
A. Krost ◽  
...  

Author(s):  
S.Y. Hwang ◽  
B.G. Seong ◽  
M.C. Kim

Abstract To maintain surface roughness of process rolls in cold rolling steel plants, WC-Co coatings have been known to be effective ones. In this study, a high pressure/high velocity oxygen fuel (HP/HVOF) process was used to obtain WC-Co coatings. To get the best quality of coatings, WC-Co coatings are sprayed with numerous powders made by various processes. These powders include agglomerated sintered powders, fused-crushed powders, extra high carbon WC-Co powders and (W2C, WC)-Co powders. After spraying, properties of coatings such as hardness, wear resistance. X-ray diffraction, and microstructures were analyzed. For coatings produced by agglomerated-sintered powders, hardness of the coating increased as power levels and the number of passes were increased. In case of the coatings produced by fused-crushed powders, a very low deposition rate was obtained due to a low flowablity of the powders. In addition, the WC-Co coatings sprayed with extra carbon content of WC-Co did not show improved hardness and wear resistance. Also, some decomposition of WC was observed in the coating. Finally, the coatings produced by (W2C, WC)-Co powders produced higher hardness and lower wear resistance coating.


Author(s):  
Michael R. Jackson ◽  
Thomas L. Selby

A recombinant metal-dependent phosphatidylinositol-specific phospholipase C (PI-PLC) fromStreptomyces antibioticushas been crystallized by the hanging-drop method with and without heavy metals. The native crystals belonged to the orthorhombic space groupP222, with unit-cell parametersa= 41.26,b= 51.86,c = 154.78 Å. The X-ray diffraction results showed significant differences in the crystal quality of samples soaked with heavy atoms. Additionally, drop pinning, which increases the surface area of the drops, was also used to improve crystal growth and quality. The combination of heavy-metal soaks and drop pinning was found to be critical for producing high-quality crystals that diffracted to 1.23 Å resolution.


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