(Ni,Ti), (Ni,Sn) and (Zn,Ti) substituted barium ferrite particles prepared by a flux method with /spl delta/-FeOOH as a precursor

BaFe/sub 12-2x/M/sub x/M'/sub x/O/sub 19/ particles, (M,M') representing (Ni,Ti), (Ni,Sn), and (Zn,Ti) were prepared by a modified flue method using /spl delta/-FeOOH as a precursor and NaCl as the flux. The substitution with (Ni,Ti), or (Ni,Sn) lowers coercivity effectively to 650 to 1600 Oe, however deteriorates saturation magnetization to the level of 25 to 45 emu/g. The substitution with (Zn,Ti) reduces both particle size and coercivity, while retaining high saturation magnetization. BaFe/sub 12-2x/Zn/sub x/Ti/sub x/O/sub 19/ (x=0.75 or 1) particles, being calcined at 950/spl deg/C to 1000/spl deg/C for 4 hours, have a coercivity of 1200 to 1880 Oe, a saturation magnetization of 59 to 62 emu/g, and an average particle size of around 100 nm with fine platelet shape. They may find applications as recording media.<
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