Abstract

GONZALEZ-ANGELES, ALVARO et al. MAGNETIC AND STRUCTURAL STUDIES OF (Sn, Ni -Sn) SUBSTITUTED BARIUM HEXAFERRITES SYNTHESIZED BY BALL MILLING. Dyna rev.fac.nac.minas [online]. 2009, vol.76, n.159, pp.61-65. ISSN 0012-7353.

Samples of BaFe_12-2x(SnSn)_xO₁₉ and BaFe_12-2x(NiSn)_xO₁₉ were processed by high energy milling with 0 ≤ x ≤ 0.4 and 0 ≤ x ≤ 0.3 respectively. Sn²⁺-Sn⁴⁺ mixture considerably improved the saturation magnetization, M_s, (from 60.9 to 66.15 A.m²/kg) and diminished quickly the intrinsic coercivity, H_ci, (381.1-72.33 kA/m) to suitable values for high-density magnetic recording applications, with low substitution values. On the other hand, the Ni²⁺-Sn⁴⁺ mixture also decreased the coercivity rapidly (diminution ~ 75%) however without enhancing the saturation magnetization. The shown differences on magnetic properties were mainly due to both magnetic nature of divalent ion and secondary phase presence. Mixtures with Sn²⁺ as partner ion diminished markedly to T_c (~21%).

Keywords : Magnetic materials; Magnetic properties; Nanocrystalline materials; substituted hexaferrites.

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