Module 2 : Systems under technological importance

Lecture 12 : Inorganic semiconductors -Magnetic materials - 2

 

  • III-V bulk semiconductors
    (In,Mn)As, (Ga,Mn)As, (Ga,Mn)N, (In,Mn)Sb,… zinc-blende structure
    focus of studies since ~ 1992

Problem: low solubility of Mn
→ low-temperature MBE:
up to ~ 8% of Mn

Mn2+ introduces spin 5/2 and
hole (shallow acceptor)

→ high hole concentration,
but partially compensated:

substitutional MnGa: acceptors
• antisites AsGa: double donors
• Mn-interstitials: double donors

Ferromagnetic samples are p-type

(In,Mn)As: Ohno et al., PRL 68, 2664 (1992)