Improving the energy product of hard magnetic materials

2002; American Physical Society; Volume: 65; Issue: 17 Linguagem: Inglês

10.1103/physrevb.65.174420

ISSN

1095-3795

Autores

Jordi Sort, S. Suriñach, J.S. Muñoz, M.D. Baró, J. Nogués, G. Chouteau, V. Skumryev, G. C. Hadjipanayis,

Tópico(s)

Magnetic and transport properties of perovskites and related materials

Resumo

A route toward enhancing the energy product $(\mathrm{BH}{)}_{\mathrm{max}}$ of permanent magnetic materials, at room temperature, based on ferromagnetic-(FM-) antiferromagnetic (AFM) exchange interactions has been developed. The exchange coupling, which is induced by ball milling hard magnetic ${\mathrm{SmCo}}_{5}$ with AFM NiO powders, results in an enhancement of coercivity ${H}_{C}$ and squareness ratio ${M}_{R}{/M}_{S}$ (remnant-saturation magnetizations), which depends on the FM:AFM ratio and the processing conditions. However, the presence of the AFM in the composite results also in a competing effect, i.e., reduction of the overall saturation magnetization, which decreases $(\mathrm{BH}{)}_{\mathrm{max}}.$ Nevertheless, it has been found that after an optimization of the FM:AFM ratio and the milling conditions it is possible to achieve an improvement of $(\mathrm{BH}{)}_{\mathrm{max}}.$

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