超微粒子フェライトの諸特性と芝草病原菌に対する生長抑制効果 [in Japanese] Some Characteristics of Ultrafine Ferrite Particles and Suppressive Effect on Turfgrass Mold [in Japanese]
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In order to study the effect of ultrafine ferrite particles on the suppression of the growth of turfgrass mold, some ferrite characteristics hava been studied and the trial experiments on the suppressive effects by the ferrites have been studied. Several kinds of ultrafine ferrite particles were prepared by coprecipitation. The lattice constants of these ferrite were almost the same as those of the bulk ferrites. The average crystal sizes of these ferrite particles were less than 30nm which was coincident with the values obtained by TEM observation. Values of the saturation magnetization, σ<SUB>5</SUB> of the ferrites prepared by coprecipitation were less than those of the bulk ferrites. This is attributed to the existence of magnetic inactive surface layer on the ferrite particles. The coecive force, <SUB>I</SUB>H<SUB>c</SUB>, of these ferrites was relevant to the magnetic anisotropy constant, K<SUB>1</SUB>, of the bulk ferrites. For MnFe<SUB>2</SUB>O<SUB>4</SUB> and ZnFe<SUB>2</SUB>O<SUB>4</SUB>, the suppression of the growth of turfgrass mold could be observed at 10°C but not so clearly observed at 25°C. For Ni<SUB>0.5</SUB>Zn<SUB>0.5</SUB>Fe<SUB>2</SUB>O<SUB>4</SUB>, the suppression of the growth of turfgrass mold was observed at both 10°C and 25°C, especially at 25°C, about 40% suppression was observed.
- J. Jpn. Soc. Powder Powder Metallurgy
J. Jpn. Soc. Powder Powder Metallurgy 46(2), 167-171, 1999-02-15
Japan Society of Powder and Powder Metallurgy