Structure of epitaxial Gd2O3 films grown on GaAs(100)

Single-crystal Gd2O3 films were grown epitaxially on GaAs(100) substrate. From the single-crystal momentum space analysis on four different samples, 185, 45, 25, and 18 Angstrom, thick, a Mn2O3 isomorphous cubic structure is identified. The Gd2O3 him aligns its twofold (110) axis with the fourfold (100) surface normal of the substrate, while aligning its [001] and [(1) over bar 10] axes with the [011] and [01 (1) over bar] axes of GaAs within the plane, respectively. The absence of the other possible twofold growth orientation can be explained by the bonding configuration at the interface. The 18- and 25-Angstrom-thick samples show an elastically strained component in the film, while thicker samples appear fully relaxed, probably through misfit dislocation formation. [S0163-1829(99)08439-8].