Magnetic Proerties of Ge/MnAs Digital Heterostructures

초록

Magnetic properties of Ge/MnAs digital heterostructure grown by molecular beam epitaxy are reported. A Ge (1 nm)/MnAs (0.15 nm) digital heterostructure exhibited ferromagnetic ordering below 335 K. More importantly, the Ge (1 nm)/MnAs (0.15 nm) heterostructure shows an n-type conductivity and an anomalous Hall effect at room temperature. Concurrently, the magnetic phase stabilities of the Ge (1 nm)/MnAs (0.15 nm) digital heterostructure have been investigated using the highly precise all-electron full-potential linearized augmented plane-wave (FLAPW) method within the generalized gradient approximation (GGA). A total energy calculations reveal that the ferromagnetic coupling between the Mn atoms is energetically favored over the antiferromagnetic (100) and (110) coupling. The Ge (1 nm)/MnAs (0.15 nm) digital heterostructure also showed a possible half-metallic ferromagnetic phase with a 0.25 eV band gap for the minority spin channel, which indicates a promising possible spintronic application.

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