針状微粒子から作製した配向性マンガン亜鉛フェライト Crystal Oriented Manganese Zinc Ferrites Made from Acicular Fine Particles
Acicular manganese zinc ferrite particles were prepared and then a sintered manganese zinc ferrite with well crystal-orientation was experimentally fabricated by using the acicular particles.<BR>As the starting materials of the acicular manganese zinc ferrite particles, the acicular α -FeOOH, Mn(C<SUB>5</SUB>H<SUB>7</SUB>O<SUB>2</SUB>)<SUB>3</SUB> and Zn(C<SUB>5</SUB>H<SUB>7</SUB>O<SUB>2</SUB>)<SUB>2</SUB> were used and the mixture of these materials were sintered at 900°C for 4 hours in a nitrogen atmosphere. The highest values obtained by measurement for the sintered particles were saturation magnetization of 68.8 emu/g (0.458 Wb/m2 ), coercivity of 81 Oe (6.5 kA/m), the length of the long axis of 2μm and aspect ratio of 15 respectively. As a result of chemical etching of the acicular particle, it has become apparent that several crystallites are linearly aligned in a particle.<BR>The acicular manganese zinc ferrite particles were pressed and formed to a shape under the magnatic field of 12 kOe (960 kA/m) by wet method, and then sintered at 1250°C in air. The sintered manganese zinc ferrite strongly exhibited a uniaxial crystal-orientation similar to that of the manganese zinc ferrite single crystal.
粉体および粉末冶金 43(1), 36-40, 1996-01-15
Japan Society of Powder and Powder Metallurgy