Magnetic powder suitable for low-noise media
An iron system magnetic powder, and particularly an iron system magnetic powder comprised chiefly of Fe 16 N 2 , is provided that has an atomic ratio of total noble metal content to Fe of 0.01-10%. The magnetic powder can be produced by subjecting iron oxy-hydroxide or iron oxide having an atomic ratio of total noble metal content to Fe of 0.01-10% to reduction treatment. The average particle volume of the magnetic powder is preferably 4,000 nm 3 or less. The magnetic powder is suitable for fabricating high recording density media of low noise, high output and high C/N ratio that are suitable for use with a GMR head or the like.
1 . An iron system magnetic powder having an atomic ratio of total noble metal content to Fe of 0.01-10%.
2 . A magnetic powder comprised chiefly of Fe 16 N 2 having an atomic ratio of total noble metal content to Fe of 0.01-10%.
3 . A magnetic powder according to claim 1 produced by subjecting iron oxy-hydroxide or iron oxide having an atomic ratio of total noble metal content to Fe of 0.01-10% to reduction treatment.
4 . A magnetic powder according to claim 2 produced by subjecting iron oxy-hydroxide or iron oxide having an atomic ratio of total noble metal content to Fe of 0.01-10% to reduction treatment and then to nitriding treatment.
5 . A magnetic powder according to claim 1 , whose average particle volume is 4,000 nm 3 or less.
6 . A magnetic recording medium that uses a magnetic powder of claim 1 in a magnetic layer.
7 . A magnetic powder according to claim 2 produced by subjecting iron oxy-hydroxide or iron oxide having an atomic ratio of total noble metal content to Fe of 0.01-10% to reduction treatment.
8 . A magnetic powder according to claim 2 , whose average particle volume is 4,000 nm 3 or less.
9 . A magnetic powder according to claim 3 , whose average particle volume is 4,000 nm 3 or less.
10 . A magnetic powder according to claim 4 , whose average particle volume is 4,000 nm 3 or less.
11 . A magnetic recording medium that uses a magnetic powder of claim 2 in a magnetic layer.
12 . A magnetic recording medium that uses a magnetic powder of claim 3 in a magnetic layer.
13 . A magnetic recording medium that uses a magnetic powder of claim 4 in a magnetic layer.
14 . A magnetic recording medium that uses a magnetic powder of claim 5 in a magnetic layer.