We report on the crystal structures, magnetic and magnetotransport properties of epitaxial (Ga1-xMnx)N films with low Mn concentration (x = 0.06-0.5%) grown by plasma-enhanced molecular beam epitaxy, exhibiting n-type conductivity and ferromagnetism with Curie temperature in the range 550-700 K. Transmission electron microscopy studies revealed that Mn ions substitute for Ga ions in the epitaxial structure, leading to the expansion of the lattice parameter a of the hexagonal (wurtzite) structure. The temperature dependence of the sheet resistance is found to show negative magnetoresistance in the temperature range 4-300 K, indicative of ferromagnetic semiconducting (Ga,Mn)N films.
Bibliographical noteFunding Information:
This work was supported by the Korea Basic Science Institute Grant (R23-2001-00020), the KIST Vision 21 Program, and the KRCF (Quantum Dots-Functional Devices). We thank Y.D. Park for helpful discussions.
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics
- Materials Chemistry