Font Size: a A A

The Research On The Microarrangments Of Hydrogen In LaNi4.5Al0.5Hx Crystal

Posted on:2007-01-08Degree:MasterType:Thesis
Country:ChinaCandidate:D ChenFull Text:PDF
GTID:2120360185993970Subject:Atomic and molecular physics
Abstract/Summary:PDF Full Text Request
Based on the Density Functional Theory and Full-potential Linearized Augmented Plane Wave (FLAPW) method, the equilibrium structure, density of states , electron density energy and bond length have been systemically calculated for the alloys LaNi4.5Al0.5 HX (x=0.5~6.0). In chapter 4 the electronic structure and geometry structure of LaNi4.75Alo.25 ternary alloys are deeply analyzed. The calculated results are well agreement with the experimental data.In order to investigate the microarrangments of hydrogen in LaNi4.5Al0.5 crystal, we built a double-cell model. By analyzing the solid solution(x=0.5,1.0,1.5), we found that the frist H atom is most likely to occupy the 6m(0.1899,0.4064,0.6317) site.The calculated result is agreement with the experiment result. The 4h*(0.3393,0.6546,0.1828) and 3f(0.3419,0.6473,0.1841) sites are the positions that the second and the third H atoms most likely to occupy. For example, the occupied sites in LaNi4.5Al0.5H1.5 crystal are 6m, 4h*and 3f. The unit cell is mainly expand in the c-axis direction. The interaction among hydrogen atoms and nickel atoms is stronger than among hydrogen atoms and aluminium atom. The interaction is weakened among lanthanum atoms and nickel atoms because of the expanded volume in the LaNi4.5Al0.5 alloy.For the first time we analysed the microarrangments of hydrogen in LaNi4.5Alo.5Hx intermediate phase (x=2.0,2.5,3.0,4.0). the results show that the 6m*(0.0622,0.1904,0.7662),3f*(0.5300,0.4896,0.0511),6m*(0.1173,0.2219,0.7610)...
Keywords/Search Tags:Density Functional Theory, Full-potential Linearized Augmented Plane Wave, Density of States, Electron Density, Solid Solution Phase(α-Phase), Intermediate Phase(β-Phase), Hydride Phase(γ-Phase), LaNi4.5Al0.5HX
PDF Full Text Request
Related items