Structural Properties of TaAs Weyl Semimetal Thin Films Grown by Molecular Beam Epitaxy on GaAs(001) Substrates

Thin crystalline layers of TaAs Weyl semimetal are grown by molecular beam epitaxy on GaAs(001) substrates. The (001) planes the tetragonal lattice parallel to substrate, but corresponding in-plane crystallographic directions substrate and layer rotated 45°. In spite a substantial mismatch (about 19%) between epilayer, no misfit dislocations observed at GaAs(001)/TaAs(001) interface. Only stacking fault defects in detected transmission electron microscopy. Thorough X-ray diffraction measurements analysis situ reflection high-energy images indicate that fully relaxed already initial deposition stage. Atomic force microscopy imaging reveals columnar structure layers, with lateral (parallel layer’s surface) columns about 20 nm wide 200 long. Both share same orientation structure.