Tuning optical and ferromagnetic properties of thin GdN films by nitrogen-vacancy centersReddithota Vidyasagar, Shinya Kitayama, Hiroaki Yoshitomi, Takashi Kita, Takahiro Sakurai and Hitoshi OhtaEur. Phys. J. B, 86 2 (2013) 52DOI: https://doi.org/10.1140/epjb/e2012-30566-3