No abstract

M-type SrFe 12-x Al x O 19(0 < x < 2.5) nanoparticles have been synthesized by citrate–nitrite sol–gel technique. The experimental results have shown that Al 3+ ions substitute Fe 3+ ions in the sublattice, and the samples remain in the hexagonal magnetoplumbite phase. The saturation magnetization Ms and remanence Mr of M-type SrFe 12-x Al x O 19(0 < x < 2.5) nanoparticles linearly decrease when x increases. x = 0, Ms = 63.5 emu/g and Ms = 23.8 emu/g at x = 2.5 when the magnets are sintered at 1100°C. Meanwhile, the coercivity Hc of the samples fluctuate as doped with Al , and reach maximum Hc = 10.59 kOe when x = 1.5. The intergranular exchange–coupling interactions between the nanoparticles, which are proved by the measurement of Henkel plots (δM), and the interactions become more intensive as the Al substitution x increases.

No abstract

No abstract