The magnetism in ∼1 at% Mn-doped nanometric Bi2Se 3 epitaxial layers has been studied by ferromagnetic resonance (FMR), magnetometry, and polarized neutron reflectivity (PNR) measurements. The FMR results reveal the formation of an intrinsic homogeneous FM bulk phase, as confirmed by the PNR measurements. Its critical temperature is low: T c ≈ 6 K; no surface magnetic phase is detected above this temperature. The FMR measurements at T = 4.2 K show a single uniform mode spectrum with a strong uniaxial in-plane/out-of-plane symmetry. The uniaxial anisotropy field at T = 4 K is Ha ∼ -2500 Oe, corresponding to a uniaxial anisotropy constant of -9 × 103 erg/cm3. The easy axis of magnetization is oriented in the film plane for temperatures between 4 K and Tc. Conduction electron-mediated FM in this (very) diluted magnetic semiconductor is considered as the most probable origin of the FM phase formation.
|Original language||English (US)|
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|State||Published - Aug 30 2013|
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics