The high magnetocrystalline phase of L1(0) FePt has received considerable attention for achieving stable magnetization states in small volumes which could increase magnetic areal storage densities. When FePt is sputter-deposited, it adopts a magnetically soft A1 phase requiring annealing to phase transform to the L1(0) phase; this annealing results in detrimental grain growth which reduces the capacity for high areal storage densities. In the current work, a series of 10 nm thick granular FePt-SiO2 thin films with various silica contents has been annealed at different fluences using a 10 ms pulse width, 1064 nm wavelength laser to determine if the silica matrix could inhibit this grain growth. The A1 to L1(0) phase transformation was confirmed by selected area electron diffraction. In general, the films annealed with approximately 25 J/cm(2) exhibited the highest L1(0) c/a tetragonality, 0.97, and coercivity of approximately 875 kA/m (11 kOe). For these films, the 38 vol.% silica incorporation resulted in a FePt grain size of approximately 8.5 nm as compared to 30 nm for films with no silica. The granular encasement of the FePt grains was effective at reducing but unable at inhibiting grain growth using single pulsed laser anneals. (C) 2012 Elsevier B. V. All rights reserved.