Influence of interface structure on electronic properties and Schottky barriers in Fe/GaAs magnetic junctions

Abstract

The electronic and magnetic properties of Fe/GaAs(001) magnetic junctions are investigated using first-principles density-functional calculations. Abrupt and intermixed interfaces are considered, and the dependence of charge transfer, magnetization profiles, Schottky barrier heights, and spin polarization of densities of states on interface structure is studied. With As-termination, an abrupt interface with Fe is favored, while Ga-terminated GaAs favors the formation of an intermixed layer with Fe. The Schottky barrier heights are particularly sensitive to the abruptness of the interface. A significant density of states in the semiconducting gap arises from metal interface states. These spin-dependent interface states lead to a significant minority spin polarization of the density of states at the Fermi level that persists well into the semiconductor, providing a channel for the tunneling of minority spins through the Schottky barrier. These interface-induced gap states and their dependence on atomic structure at the interface are discussed in connection with potential spin-injection applications.

9 pages, 9 figures, to appear in PRB

References in corpus (7)

• Theory of electrical spin injection: Tunnel contacts as a solution of the conductivity mismatch problem
• Efficient Electrical Spin Injection from a Magnetic Metal / Tunnel Barrier Contact into a Semiconductor
• The GaAs Equilibrium Crystal Shape from First-Principles
• Spin Injection and Relaxation in Ferromagnet-Semiconductor Heterostructures
• Ballistic Spin Injection from Fe(001) into ZnSe and GaAs
• First-principles study of nucleation, growth, and interface structure of Fe/GaAs
• First Principles Calculations of Fe on GaAs (100)

Cited by in corpus (6)

• Reversal of spin polarization in Fe/GaAs (001) driven by resonant surface states: First-principles calculations
• First-Principles Theory for Schottky Barrier Physics
• Spin-injection spectra of CoFe/GaAs contacts: dependence on Fe concentration, interface and annealing conditions
• Ab initio study of the interface properties of Fe/GaAs(110)
• Ferromagnet/Semiconductor/Ferromagnet Hybrid Trilayers grown using solid phase epitaxy
• Perspectives in spintronics: magnetic resonant tunneling, spin-orbit coupling, and GaMnAs