Investigation on microstructure and magnetic properties of (Fe50Co50)73.5Cu1Nb3Si13.5B9

We prepared (Fe<inf>50</inf>Co<inf>50</inf>)<inf>73.5</inf>Cu<inf>1</inf>Nb<inf>3</inf>Si<inf>13.5</inf>B<inf>9</inf> amorphous ribbons and annealed that under different temperatures. Atom Force Microscope (AFM) was used to analyze its micro morphology. The AFM figures indicated the grain size of Co-doped Finemet alloy annealed at 540°C grew finer which attributes to the addition of Co. The complex permeability was measured by soft magnetic properties measuring system. The optimal soft magnetic properties can be obtained when (Fe<inf>50</inf>Co<inf>50</inf>)<inf>73.5</inf>Cu<inf>1</inf>Nb<inf>3</inf>Si<inf>13.5</inf>B<inf>9</inf> were annealed at a temperature range of 480∼520°C.