Z型六方晶Baフェライト(Ba_3Co_<2-X>Fe_<24+X>O_<41>)の相安定性と磁気特性 [in Japanese] Thermally Stable Region and Magnetic properties of Z-type Hexagonal Ferrite : Ba_3Co_<2-X>Fe_<24+X>O_<41> [in Japanese]
Access this Article
Search this Article
Conditions for synthesizing single phase materials of the hexagonal Z-type were investigated by preparing samples with various compositions (x=0, 0.2, 0.4, 0.6 in Ba<SUB>3</SUB>Co<SUB>2-x</SUB>Fe<SUB>24+x</SUB>O<SUB>41</SUB>) and oxygen partial pressures, P<SUB>O2</SUB>=21.3, 31.3, 41.3, 61.3, 101.3 kPa, at T=1573 K. The phases formed in the samples were examined by X-ray diffraction technique and the dc magnetization was measured as a function of temperature by a vibrating sample magnetometer (VSM) at a magnetic field of 5.6 kA/m. The correlation between the phases occurring in the samples and the complex permeability μ, at 100MHz was investigated, and it was indicated that high μ<SUB>r</SUB> is obtained when the hexagonal Z-type occurs without any other phase. The highest μ<SUB>r</SUB>=20 was obtained with conditions of x =0.2, P<SUB>O2</SUB>=101.3 at 1573 K. The neutron diffraction patterns were measured between 294 and 773 for the sample of x=0.4. Two significant magnetic Bragg reflections were observed in the pattern measured at 294 K, but no peak at 773 K. Integrated intensities of the magnetic scattering peaks were plotted against temperatures, which was consistent with the magnetization vs. temperature curve measured with VSM. It was indicated that the hexagonal Z-type phase exhibits two stage magnetic transition at 500-540 and 680 K.
- Journal of the Japan Society of Powder and Powder Metallurgy
Journal of the Japan Society of Powder and Powder Metallurgy 49(2), 129-134, 2002-02-15
Japan Society of Powder and Powder Metallurgy