Raman scattering and ferromagnetism of (Ga, Mn)N films grown by MOCVD

In this letter, Raman spectra for a series of (Ga, Mn)N samples with different Mn concentration grown by MOCVD have been investigated. A new vibrational mode at 577 cm−1 obtained is assigned to the local vibrational mode (LVM) of Mn substituting the Ga site. Another mode at 667 cm−1 arises from vibrational mode of nitrogen vacancies-related defects. It is found that Mn doping increases the lattice disorder and other built-in defects such as the nitrogen vacancies. The room temperature ferromagnetism is not only dependent on the substitutional Mn content but also strongly related to these lattice disorder and negative defects in (Ga, Mn)N films.