Manganese 3×3 and3×3-R30∘str

Abstract

Manganese deposited on the N-polar face of wurtzite gallium nitride [GaN (0001)] results in two unique surface reconstructions, depending on the deposition temperature. At lower temperature (less than 105• C), it is found that a metastable 3 × 3 structure forms. Mild annealing of this Mn 3 × 3 structure leads to an irreversible phase transition to a different, much more stable• structure which can withstand hightemperature annealing. Scanning tunneling microscopy (STM) and reflection high-energy electron diffraction data are compared with results from first-principles theoretical calculations. Theory finds a lowest-energy model for the 3 × 3 structure consisting of Mn trimers bonded to the Ga adlayer atoms but not with N atoms. The lowest-energy model for the more stable √ 3 × √ 3-R30• structure involves Mn atoms substituting for Ga within the Ga adlayer and thus bonding with N atoms. Tersoff-Hamman simulations of the resulting lowest-energy structural models are found to be in very good agreement with the experimental STM images.

Properties of Bare and Thin-Film-Covered GaN(0001) Surfaces

“…The studies were inspired by the spintronic potential of MnGaN alloys [12][13][14]. Thin films of Mn on GaN have mainly been reported for the (0001) N-terminated surfaces [18][19][20][81][82][83]. These works generally refer to structural analysis for ultra-thin coverage.…”

Properties of Thin Film-Covered GaN(0001) Surfaces

“…The studies were inspired by spintronic potential of MnGaN alloys [12][13][14]. Thin films of Mn on GaN have mainly been reported for the (0001 ), N-terminated, surfaces [18][19][20][81][82][83]. These works, generally, referred to structural analysis for ultra-thin coverages.…”

A Two-Dimensional Manganese Gallium Nitride Surface Structure Showing Ferromagnetism at Room Temperature

“…In previous work, we have shown that depositing ∼0.4 ML of Mn on GaN(0001) 1 × 1 at ∼200 °C forms a √3 × √3 − R30°surface structure (MnGaN-2D). 39 The successful preparation of the MnGaN-2D structure is indicated by its signature RHEED pattern immediately appearing upon Mn deposition (Supporting Information Figure S1E,F).…”