Transition metal synthetic ferrimagnets: tuneable media for all-optical switching driven by nanoscale spin current por Dabrowski, M, Scott, JN, Hendren, WR, Forbes, CM, Frisk, A, Burn, DM, Newman, DG, Sait, CRJ, Keatley, PS, N'Diaye, AT, Hesjedal, T, van der Laan, G, Bowman, RM, Hicken, RJ