The crystallographic and magnetic properties of porous NixZn1-xFe2O4 (x = 0.1, 0.5 and 0.9) from wood templates were investigated in this study. The nitrates aqueous precursor solution was infiltrated into the wood specimen at 60°C to retain the original shape and the microstructure of wood. The sintered bodies contained elongated pores enclosed by a thin layer of wall with the thickness about 1-2 μm. The grain size of polycrystalline ferrite was observed to be in the range of 1-1.5 μm. Each grain was horizontally connected to form polycrystalline walls of single-layered grains. The VSM measurement showed that there is an obvious difference of magnetic properties in the parallel and perpendicular direction due to the anisotropic structure of wood template. The coercivity perpendicular to the pores orientation was larger compared to the coercivity parallel to the pores orientation. It is also discovered that the optimum saturation magnetization was achieved at x = 0.5.

10.2109/jcersj2.117.958

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Citations (10)

PTC Characteristic and Percolation of Conductor-Filled Polymers

NIPPON GOMU KYOKAISHI (2004)

Toshitaka Ota

The electrical conductivity and the PTC (positive temperature coefficient of resistivity) characteristic of conductor-filled polymers are reviewed. In order to interpret the electrical conductivity (resistivity) as a function of the volume fraction for binary composites, percolation and effective media theories, and a genaral effective media (GEM) equation which combines most aspects of both percolation and effective media theories, are introduced, and compared with experimental data of some composites such as phenol resin/copper and silicone rubber/copper. In addition, models based on the packing behavior of the filler and polymer particles are presented to predict critical volume fractions for conduction in conductor-filled polymers, where the electrical resistivity suddenly decreases.

Percolation (cognitive psychology)

Volume fraction

Percolation Theory

Silicone rubber

10.2324/gomu.77.48

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Microstructure Control of Silica Thin Film by Spin Coating Method

Key engineering materials (2001)

Tomoya Ohno Hisao Suzuki Junichi Takahashi Shirou Shimada Toshitaka Ota

Spin Coating

10.4028/www.scientific.net/kem.206-213.2185

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Citations (2)

Correlation between a dielectric anomaly and a phase transition of sintered phosphorus doped WO<sub>3</sub> ceramics

Journal of the Ceramic Society of Japan (2013)

Atsushi Nose Hidetoshi Miyazaki Y. Akishige Shinya Tukada Hisao Suzuki

Phosphorus doped WO3 (PxW1−xO3) ceramics were fabricated by a solid state reaction. Temperature and frequency dependence of dielectric properties for the PxW1−xO3 (x = 0–0.15) ceramics were evaluated at the temperature between −20 to 80°C. The dielectric constant of the P0.05W0.95O3 ceramic was 3600–5800 at the frequency range from 1 kHz to 1 MHz in the room temperature, and the dielectric loss of the P0.05W0.95O3 ceramic were less than 0.1 at the frequency of higher than 160 kHz. The dielectric anomaly peak of the WO3 ceramic has been observed at 20°C, and the dielectric anomaly peak of the P0.05W0.95O3 ceramic has been observed at about 0°C. The interaction between temperature dependence of dielectric properties (dielectric anomaly) ceramics and structural change of the WO3 and P0.05W0.95O3 were evaluated by Raman spectra.

Anomaly (physics)

Atmospheric temperature range

10.2109/jcersj2.122.25

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Citations (1)

LaPO 4 -Containing Machinable Al 2 O 3 Ceramics

Phosphorus, sulfur, and silicon and the related elements (2002)

Yasuo Hikichi Keiji Daimon Toshitaka Ota

(2002). LaPO 4 -Containing Machinable Al 2 O 3 Ceramics. Phosphorus, Sulfur, and Silicon and the Related Elements: Vol. 177, No. 8-9, pp. 1915-1915.

10.1080/10426500213309

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Citations (1)