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Using density-functional ab initio calculations, we provide a revised phase diagram of (Ga$_{1-x}$In$_{x})_2$O$_3$. Three phases --monoclinic, hexagonal, cubic bixbyite-- compete for the ground state. In particular, in the $x$$sim$0.5 region we expect coexistence of hexagonal, $beta$, and bixbyite (the latter separating into binary components). Over the whole $x$ range, mixing occurs in three disconnected regions, and non-mixing in two additional distinct regions. We then explore the permanent polarization of the various phases, finding that none of them is polar at any concentration, despite the possible symmetry reductions induced by alloying. On the other hand, we find that the $varepsilon$ phase of Ga$_2$O$_3$ stabilized in recent growth experiments is pyroelectric --i.e. locked in a non-switchable polarized structure-- with ferroelectric-grade polarization and respectable piezoelectric coupling. We suggest that this phase could be used profitably to produce high-density electron gases in transistor structures.
Based on first-principles calculations, we show that the maximum reachable concentration $x$ in the (Ga$_{1-x}$In$_x$)$_2$O$_3$ alloy in the low-$x$ regime (i.e. In solubility in $beta$-Ga$_2$O$_3$) is around 10%. We then calculate the band alignment
Using density-functional ab initio theoretical techniques, we study (Ga$_{1-x}$In$_x$)$_2$O$_3$ in both its equilibrium structures (monoclinic $beta$ and bixbyite) and over the whole range of composition. We establish that the alloy exhibits a large
We report results of the dielectric and pyroelectric measurements on solid solutions of Ga$_2$$_-$$_x$Fe$_x$O$_3$ with x = 0.75, 1.0 and 1.25. These systems exhibit dipolar cluster glass behavior in addition to the spin glass behavior making them bel
$beta$-Ga$_2$O$_3$ is a promising ultra-wide bandgap semiconductor whose properties can be further enhanced by alloying with Al. Here, using atomic-resolution scanning transmission electron microscopy (STEM), we find the thermodynamically-unstable $g
I use first principles calculations to investigate the thermal conductivity of $beta$-In$_2$O$_3$ and compare the results with that of $alpha$-Al$_2$O$_3$, $beta$-Ga$_2$O$_3$, and KTaO$_3$. The calculated thermal conductivity of $beta$-In$_2$O$_3$ ag