Use of a standard reference material for precise lattice parameter determination of materials of hexagonal crystal structure

1987 ◽  
Vol 6 (12) ◽  
pp. 1443-1444 ◽  
Author(s):  
N. A. Razik
2019 ◽  
Vol 2 (1) ◽  
pp. 15
Author(s):  
Vivi Hastuti Rufa Mongkito ◽  
Muhammad Anas ◽  
Wisda Puspita Bahar

This research aims to determine the effect of activation temperature the crystal structure of activated charcoal. The material used activated charcoal bunches (Arengga Pinnate Merr). The process of making activated charcoal divided into two, namely the carbonization stage at a temperature of 250- 400 oC and the activation stage at a temperature variation of 600 - 800 ̊C. To find the crystal structure, the sample characterized by X-Ray Diffraction. The results of analysis the dominant elements diamond before activation with a percentage of 90.2% and an orthorhombic crystalline structure, where the lattice parameter a = 4.12700 Å; b = 4.93700 Å; c = 4.81900 Å. Peak Carbon has a hexagonal crystal structure in all temperature variations. Peak Graphite an orthorhombic crystal structure and at a temperature of 700 oC a hexagonal crystal structure formed. Therefore, giving temperature variations the activated charcoal of the bunches affects the structure of the formed Crystal. Wherein increasing the activation temperature, the crystal structure that forms look more amorphous marked by a widening diffraction peak intensity decreased crystals


1988 ◽  
Vol 3 (1) ◽  
pp. 8-15
Author(s):  
Raghavan Ayer ◽  
J. C. Scanlon ◽  
M. Watkins ◽  
G. A. Vaughn ◽  
J. W. Steeds

A new hexagonal crystal structure modification of the rhombohedral Mu phase with A7B6 stoichiometry was observed in a cast alloy C-276. The hexagonal structure was determined to share the same lattice parameter along the a axis, while the dimension along the c axis was such that chex = 2/3crhomb. The space group of the hexagonal phase is suggested to be P 63/mmc and forms by a four-layer ABAB repeat, where A and B represent Zr4Al3 and MgCu2 structures, respectively. Details of the diffraction analysis are presented in this article.


2020 ◽  
Vol 10 (24) ◽  
pp. 8776
Author(s):  
Sheng-Fang Huang ◽  
Yen-Cheng Chang ◽  
Po-Liang Liu

A new ternary compound Cu2SnTi3 has been synthesized by vacuum sintering at 900 °C. The atomic structures of CaCu5- and InNi2-like Cu2SnTi3 are calculated using density functional theory methods. The X-ray diffraction (XRD) analysis and selected area diffraction (SAD) patterns of the new ternary compound Cu2SnTi3 are considered to verify the atomic structures of CaCu5- and InNi2-like Cu2SnTi3. The results reveal that the InNi2-like Cu2SnTi3 model has the lowest total energy of −35.239 eV, representing the trigonal crystal structure. The orthorhombic crystal structure of the CaCu5-like Cu2SnTi3 model has the second lowest total energy of −33.926 eV. Our theoretical X-ray diffraction peak profiles of InNi2-like (CaCu5-like) Cu2SnTi3 are nearly identical to experimental one, leading to an error below 2.0% (3.0%). In addition, the hexagonal crystal structure of the CaCu5-like Cu2SnTi3 model has the highest total energy of −33.094 eV. The stability of the Cu2SnTi3 in terms of energy follows the order: the trigonal, orthorhombic, and hexagonal crystal structure.


2004 ◽  
Vol 10 (S02) ◽  
pp. 310-311
Author(s):  
Takayuki Akaogi ◽  
Kenji Tsuda ◽  
Masami Terauchi ◽  
Michiyoshi Tanaka

Extended abstract of a paper presented at Microscopy and Microanalysis 2004 in Savannah, Georgia, USA, August 1–5, 2004.


2010 ◽  
Vol 152-153 ◽  
pp. 674-678 ◽  
Author(s):  
Bing Wang ◽  
Li Dan Tang ◽  
Jian Zhong Wang

Nanocrystalline ZnO powders have been synthesized by a novel combustion synthesis method using glycine and urea as mixed fuels and zinc nitrates as oxidant. The as-synthesized ZnO powders are characterized by DSC, XRD and SEM. Results show that the as-synthesized ZnO powders show well crystalline with hexagonal crystal structure and purity without any other impurities and the particle sizes are about 50~70nm calculated by the Scherrer formula.


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