Crystallization and structural relaxation of Fe78−xPtxB10Si12 metallic glasses

Fe 78-x Pt x B 10 Si 12 (x = 0, 5, 15, 25) metallic glasses were produced to investigate the effects of Pt on the thermally annealed microstructure and ensuing magnetic properties of the alloy. The Pt addition progressively lowered the glass stability and accelerated the onset of devitrification. Final crystallization products contained either Fe 3 Pt or FePt, depending on the Pt content together with Fe-borides. A maximum coercivity of 1140 Oe was obtained with the Fe 63 Pt 15 B 10 Si 12 alloy annealed at 500 °C due to the precipitation of elongated FePt crystals. Measurements of the saturation magnetization of the annealed alloys gave an indication that the amorphous structure may have undergone structural relaxation prior to devitrification.