Superionic Conduction in Substoichiometric LiAl Alloy: An Ab Initio Study

Cucinotta, Clotilde S. and Miceli, Giacomo and Raiteri, Paolo and Krack, Mattias and Kuhne, Thomas D. and Bernasconi, Marco and Parinello, Michele. 2009. Superionic Conduction in Substoichiometric LiAl Alloy: An Ab Initio Study. Physical Review Letters 103: pp. 125901-1-125901-4.

Source Title

Physical Review Letters

DOI

10.1103/PhysRevLett.103.125901

ISSN

0031 9007

Faculty

Nanochemistry Research Institute (NRI

Faculty of Science and Engineering

School

Nanochemistry Research Institute (Research Institute)

Remarks

URI

http://hdl.handle.net/20.500.11937/28706

Collection

Curtin Research Publications

Abstract

Based on the new ab initio molecular dynamics method by Kuhne et al. [Phys. Rev. Lett. 98, 066401 (2007)], we studied the mechanism of superionic conduction in substoichiometric Li-poor Li1xAl alloys by performing simulations at different temperatures for an overall simulation time of about 1 ns. The dynamical simulations revealed the microscopic path for the diffusion of Li vacancies. The calculated activation energy (0.11 eV) and the prefactor (D0=6:9 x 10-4 cm2/s) for Li diffusivity via a vacancy-mediated mechanism are in good agreement with experimental NMR data. The calculation of the formation energies of different defects-Li and Al Frenkel pair and Li antisites- revealed that only Li vacancies and LiAl antisites are present in the stability range of the Zintl phase -0.1 <x<0.2.