Dilute magnetic semiconductors based on InN

We present growth and characterization of Cr-doped InN by plasma assisted molecular beam epitaxy. The films were grown on c-plane sapphire substrates, employing GaN intermediate layers to accommodate the lattice mismatch between InN and sapphire. X-ray diffraction and Hall measurements were used for structural and electrical characterization of the films. The magnetic properties were measured using superconducting quantum interference device magnetometry. Cr∈:∈InN displayed long range ferromagnetic order up to room temperature without indications of phase separation. A optimal Cr-doping regime was found around 1-2% where the effective magnetic moment per Cr atom was maximal and the paramagnetic background signal of the samples was minimal.