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Formation of hexagonal, platelike Ba-ferrite particles with low temperature dependence of coercivity

1993; Elsevier BV; Volume: 120; Issue: 1-3 Linguagem: Inglês

10.1016/0304-8853(93)91280-k

1873-4766

Nobuyuki Nagai, N. Sugita, Masahiko Maekawa,

Aluminum Alloys Composites Properties

Abstract Ba ferrite (Ba-Fe) has been prepared with a temperature coefficient of coercivity ( d H c d ) of 0 ≈−1 caseOe °C , in temperature range 0–80°C and coercivity range 500–1500 Oe. Superfine and platelike Ba-Fe particles containing Ti (IV) Ni (II) and Zn (II) were prepared by a wet method to examine their properties, using X-ray diffraction (XRD), transmission electron microscopy (TEM) and vibrating-sample magnetometry (VSM). A magnetically oriented sheet was prepared in order to examine SFD (SFD r ), SQ, S ∗ ( S ∗ r ) and the easy magnetization axis. It was found that Ni-Ti-Zn substituted Ba-Fe retains the characteristics of Co-Ti-substituted Ba-Fe. An environmental aging test of the particles also showed evidence of excellent stability. We conclude that Ni-Ti-Zn substituted Ba-Fe is suitable not only for existing magnetic recording media but also for future applications.