Superparamagnetism and magnetic properties of Ni nanoparticles embedded in 'SiO IND.2' - Fonseca, F C; Goya, Gerardo Fabían; Jardim, Renato de Figueiredo; Muccillo, R; Carreño, N L V; Longo, E; Leite, E R (Physical Review B, 2002)