English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

A first-principles computational study is presented of various phases ofLiAlO$_2$.The $\beta$ and $\gamma$ tetrahedral phases are found to be veryclose in energy with the $\gamma$ phase having the lowest energy. Theoctahedral $\alpha$ phase is a high-pressure phase and the transition pressurefrom the $\gamma$ and $\beta$ phases to $\alpha$ is determined to be about 1GPa. The electronic band structures are determined using the quasiparticleself-consistent (QS) $GW$ method. The effective masses of the band edges andthe nature of the band gaps are presented. The lowest energy $\gamma$ phase isfound to have a pseudodirect gap of 7.69 eV. The gap is direct at $\Gamma$ butcorresponds to a dipole forbidden transition. The imaginary part of thedielectric function and the absorption coefficient are calculated in thelong-wavelength limit and the random phase approximation, without local fieldor electron-hole interaction effects for each phase and their anisotropies arediscussed. Si doping on the Al site is investigated as a possible $n$-typedopant in $\gamma$-LiAlO$_2$ using a 128 atom supercell corresponding to 3.125\% Si on the Al sublattice in the generalized gradient approximation and asmaller 16 atom cell with 25 \% Si in the QS$GW$ approximation. The Si is foundto significantly perturb the conduction band and lower the gap but a clearlyseparated deep donor defect level is not found. However, the donor bindingenergy is still expected to be relatively deep, of order a few 0.1 eV in thehydrogenic effective mass approximation.

Quasiparticle self-consistent $GW$ band structures and phase transitions of LiAlO$_2$ in tetrahedrally and octahedrally coordinated structures