Recently reported room-temperature ferromagnetic (FM) semiconductors Cd1-xMnxGeP2 and Zn1-xMnxGeP2 point to a possible important role of II-IV-V2 chalcopyrite semiconductors in "spintronic" " studies. Here, structural, electronic, and magnetic properties of (i) Mn-doped II-Ge-VI2 (II=Zn or Cd and V=P or As) chalcopyrites and (ii) the role of S as impurity in Cd1-xMnxGeP2 are studied by first-principles density functional calculations. We find that the total energy of the antiferromagnetic (AFM) state is lower than the corresponding FM state for all systems with Mn composition x = 0.25, 0.50, and 1.0. This prediction is in agreement with a recent experimental finding that Zn1-xMnxGeP2 experiences a FM to AFM transition for T less than 47 K. Furthermore, a possible transition to the half-metallic FM phase is predicted in Cd1-xMnxGeP2 due to the electrons introduced by n-type S doping, which indicates the importance of carriers for FM coupling in magnetic semiconductors. As expected, the total magnetic moment for the FM phase is reduced by one μB with each S substituting P.
|Original language||English (US)|
|Number of pages||6|
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|State||Published - Mar 1 2002|
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics