Magnetic Property and Stability of Zn/Sm2Fe17Nx Bonded Magnets Using the In Metal Derived from In(C2H5)3 as a Binder

Fine powders of Sm{sub 2}Fe{sub 17}N{sub x} were stabilized by microcapsulation with the In and Zn metals produced via photochemical decompositions of In(C{sub 2}H{sub 5}){sub 3} and Zn(C{sub 2}H{sub 5}){sub 2} under UV light irradiation in an organic solvent to avoid any additional oxidation of them. After the coating treatment, they still recorded high remanence (B{sub r} = {approximately}1.30 T) and coercivity (H{sub cj} = {approximately}0.74 MA m{sup {minus}1}) values to provide maximum energy products of (BH){sub max} = {approximately}279 kJ m{sup {minus}3} despite the dilution effect by existence of the nonmagnetic In and/or Zn metals used for the protection. The photochemical decomposition of In(C{sub 2}H{sub 5}){sub 3} was smoothly performed compared with the case of Zn(C{sub 2}H{sub 5}){sub 2}, so that a large amount of In metal was deposited on the surface of Sm{sub 2}Fe{sub 17}N{sub x} fine particles ({approximately}6.5 wt %) to be sufficient for serving as a metal binder for compression-type bonded magnets without any further addition of the same metals with low melting points. The single-layered metal-coated In/Sm{sub 2}Fe{sub 17}N{sub x} and double-layered metal-coated In/Zn/Sm{sub 2}Fe{sub 17}N{sub x} powders produced the corresponding In metal-bonded Sm{sub 2}Fe{sub 17}N{sub x} and Xn/Sm{sub 2}Fe{sub 17}N{sub x} magnets, of whichmore » the latter ones provided the highest (BH){sub max} value of {approximately}144 kJ m{sup {minus}3} among a series of metal-bonded Sm{sub 2}Fe{sub 17}N{sub x} magnets reported to date.« less