Abstract
In this study, a first-principles search for the possible hydrides with the prepreerence sites of hydrogen in AB 2 C14 type
Laves structure was carried out for the Sc-Mn-H system. The obtained structural parameters were close to the available experimental results. Total energy was calculated by ab initio pseudopotential method within the generalized gradient approximation (GGA) to density functional theory (DFT). Formation energies of ScMn2Hx (x =0.75-3) hydrides are systematically investigated to analyze the influence of the hydrogen content and hydrogen sites in the alloy on the site
preference of hydrogen in the hydride s on the basis of crystal and electronic structures and structural stability. The calculated results show that ScMn 2 H 0.75 with the P3 space group has the highest stability for all hydrides. The density of states, the charge density distribution were investigated in order to get insight into t he underlying mechanism for structural stability, electronic bonding nature of ScMn 2 H x an d the preference of hydrogen entering into C14 type Laves structure structure. The results show that the prepreerence site of H atom in C14 type Laves structures is 3d(x 2x z) site in P 3 ( No.143) space group..
Keywords
ScMn2Hx, Hydrogen site, Stability, Electronic structure, FFirst-principles calculations.
Citation
DU XIAOMING, MA PING, WU ERDONG, Ab initio investigation of ScMn2-H system, Optoelectronics and Advanced Materials - Rapid Communications, 8, 3-4, March-April 2014, pp.292-299 (2014).
Submitted at: Oct. 23, 2013
Accepted at: March 13, 2014