Control of the Schottky barrier height in epitaxial magnetic MnAs/n-GaAs and MnSb/n-GaAs contacts

We explore the possibility of modifying the Schottky barrier height ill mag netic contacts to,n-GaAs, which may have implications for future spin injec tion applications. Epitaxial MnAs and MnSb are used as a test system. The s ubstrate orientation has a strong impact, with rectifying characteristics f or contacts on GaAs(0 0 1) and GaAs(1 1 1)B, but nearly Ohmic behaviour on GaAs(l I 1)A, The insertion of Si interface dipoles is not very effective i n this material system, (C) 2001 Elsevier Science B.V. All rights reserved.