Ternary diamond-like compounds in II-IV-V2 semiconductor system heavily-doped with transition d-element Mn have been recently prepared. The materials grown in both forms - single crystal layers and polycrystalline bulks -exhibit well defined ferromagnetic hysteresis with a saturation behavior in the magnetization curve up to above room temperature. Curie temperatures are of TC = 310 K to 320 K for (Cd1-xMnx)GeP 2 and (Zn1-xMnx)GeP2 compounds. The chemical states in the bulk of ZnGeP2:Mn and interface of Mn-doped ferromagnetic layer on ZnGeP2 (001) crystal, have been clarified by electron paramagnetic resonance and in situ photoemission spectroscopy. The as-prepared surface consists of Ge-rich, metallic Mn-compound. In and below the subsurface region, dilute Mn2+ species as precursors of the DMS phase exist. Mn2+ ions are paramagnetic active on Zn2+ sites in the bulk and show five EPR sets of equidistant peaks. Theoretical band-gap calculation suggests a predominant antiferromagnetic order in stoichiometric (Cd, Mn)GeP2 but the systems with vacancies as (Cd, VC, Mn)GeP2 or (Cd, Ge, Mn)GeP2 are ferromagnetic and energetically stable. These materials are of great promise for room-temperature spintronics applications.
ASJC Scopus subject areas
- Materials Science(all)
- Condensed Matter Physics
- Computer Science Applications
- Electrical and Electronic Engineering