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 Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

Nominally phase-pure $\gamma$-$Ga_2O_3$ was deposited on (100) $MgAl_2O_4$within a narrow temperature window centered at $\sim$470 $^{\circ}$C usingmetal-organic chemical vapor deposition (MOCVD). The film deposited at 440$^{\circ}$C exhibited either poor crystallization or an amorphous structure;the film grown at 500 $^{\circ}$C contained both $\beta$-$Ga_2O_3$ and$\gamma$-$Ga_2O_3$. A nominally phase-pure $\beta$-$Ga_2O_3$ film was obtainedat 530 $^{\circ}$C. Atomic-resolution scanning transmission electron microscopy(STEM) investigations of the $\gamma$-$Ga_2O_3$ film grown at 470 $^{\circ}$Crevealed a high density of antiphase boundaries. A planar defect modeldeveloped for $\gamma$-$Al_2O_3$ was extended to explain the stacking sequencesof the Ga sublattice observed in the STEM images of $\gamma$-$Ga_2O_3$. Thepresence of the 180$^{\circ}$ rotational domains and 90$^{\circ}$ rotationaldomains of $\beta$-$Ga_2O_3$ inclusions within the $\gamma$-$Ga_2O_3$ matrix isdiscussed within the context of a comprehensive investigation of the epitaxialrelationship between those two phases in the as-grown film at 470 $^{\circ}$Cand the same film annealed at 600 $^{\circ}$C. The results led to thehypotheses that (i) incorporation of certain dopants including Si, Ge, Sn, Mg,Al, and Sc, into $\beta$-$Ga_2O_3$, locally stabilizes the "$\gamma$-phase" and(ii) the site preference(s) for these dopants promotes the formation of the"$\gamma$-phase" and/or $\gamma$-$Ga_2O_3$ solid solutions. However, in theabsence of such dopants, pure $\gamma$-$Ga_2O_3$ remains the least stable$Ga_2O_3$ polymorph, as indicated by its very narrow growth window, lowergrowth temperatures relative to other $Ga_2O_3$ polymorphs, and the largestcalculated difference in Helmholtz free energy per formula unit between$\gamma$-$Ga_2O_3$ and $\beta$-$Ga_2O_3$ than all other polymorphs.

Atomic-scale investigation of $\gamma$-Ga$_2$O$_3$ deposited on MgAl$_2$O$_4$ and its relationship with $\beta$-Ga$_2$O$_3$