Jump to main content
Jump to site search


Phonons, phase transitions and thermal expansion in LiAlO2: an ab initio density functional study

Author affiliations

Abstract

We have used the ab initio density functional theory technique to understand the phase transitions and structural changes in various high temperature/pressure phases of LiAlO2. The electronic band structure as well as phonon spectra is calculated for various phases as a function of pressure. The phonon entropy used for the calculations of Gibbs free energy is found to play an important role in the phase stability and phase transitions among various phases. A sudden increase in the polyhedral bond lengths (Li/Al–O) signifies the change from the tetrahedral to octahedral geometry at high-pressure phase transitions. The activation energy barrier for the high-pressure phase transitions is calculated. The phonon modes responsible for the phase transition (upon heating) from high pressure phases to ambient pressure phases are identified. Moreover, ab initio lattice dynamics calculations in the framework of quasi-harmonic approximations are used to study the anisotropic thermal expansion behavior of γ-LiAlO2.

Graphical abstract: Phonons, phase transitions and thermal expansion in LiAlO2: an ab initio density functional study

Back to tab navigation

Publication details

The article was received on 06 Mar 2018, accepted on 11 Apr 2018 and first published on 11 Apr 2018


Article type: Paper
DOI: 10.1039/C8CP01474D
Citation: Phys. Chem. Chem. Phys., 2018, Advance Article
  •   Request permissions

    Phonons, phase transitions and thermal expansion in LiAlO2: an ab initio density functional study

    B. Singh, M. K. Gupta, R. Mittal and S. L. Chaplot, Phys. Chem. Chem. Phys., 2018, Advance Article , DOI: 10.1039/C8CP01474D

Search articles by author

Spotlight

Advertisements