Faculty Profiles - NAKANISHI Makoto

MISC - NAKANISHI Makoto

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Preparation and Characterization of (001) and (110)-Oriented Fe1.4Ti0.6O3 Films

T. Fujii, T. Sugano, Y. Takada, M. Nakanishi, J. Takada

Mater. Res. Soc. Symp. Proc. 1119 L04-09-1-6 2009

Characteristics of hollow microtubes consisting of amorphous iron oxide nanoparticles produced by iron oxidizing bacteria, Leptothrix ochracea (vol 310, pg 2405, 2007)

H. Hashimoto, S. Yokoyama, H. Asaoka, Y. Kusano, Y. Ikeda, M. Seno, J. Takada, T. Fujii, M. Nakanishi, R. Murakami

JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS 320 ( 18 ) 2310 - 2310 2008.9

21pPSA-8 Preparation and characterization of (001)- and (110)-oriented Fe_<2-x>Ti_xO_3 films for room temperature magnetic semiconductors

Sugano T., Takada Y., Fujii T., Nakanishi M., Takada J.

Meeting abstracts of the Physical Society of Japan 63 ( 2 ) 386 - 386 2008.8

21pPSA-59 Synthesis and properties of Ge substituted FeTiO_3

Nakatsuka D., Fujii T., Nakanishi M., Takada J.

Meeting abstracts of the Physical Society of Japan 63 ( 2 ) 399 - 399 2008.8

Morphological and microstructural study of iron oxide microtubes formed by iron oxidizing bacteria, Leptothrix ochracea

H. Hashimoto, S. Yokoyama, H. Asaoka, Y. Kusano, Y. Ikeda, M. Seno, J. Takada, T. Fujii, M. Nakanishi, R. Murakami

A Global Road Map for Ceramic Materials and Technologies: Forecasting the Future of Ceramics, International Ceramic Federation - 2nd International Congress on Ceramics, ICC 2008, Final Programme 6-P-011-1-6-P-011-4 2008

Characterization of biogenic iron oxide sheaths produced by Leptothrix ochracea (L. ochracea) was investigated. The sheaths had average inner- and outer-diameters of 1.08 ± 0.15 and 1.35 ± 0.14 μm, respectively. Their length ranged from 10-2000 μm. Outer and inner surface of each sheath were composed of fibrous and spherical particles, respectively. The width of fibrous particles was approx. 20 nm, while the diameter of spherical particles was 20-120 nm. The chemical composition of the sheaths was Fe: Si: P = 73: 22: 5 with the exception of H and O. The sheaths had similar structure to that of 2-line ferrihydrite.

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Structure, Morphology and Color Tone Properties of theNeodymium Substituted Hematite

Tarequl Islam Bhuiyan, Nakanishi Makoto, Fujii Tatsuo, Takada Jun

Memoirs of the Faculty of Engineering, Okayama University 41 ( 1 ) 93 - 98 2007.1

Preparation and characterization of ilmenite-hematite thin films

Y. Takada, M. Nakanishi, T. Fujii, J. Takada

Journal of Magnetism and Magnetic Materials 310 ( 2 SUPPL. PART 3 ) 2108 - 2110 2007

Ilmenite-hematite solid solution (Fe Ti O ) is one of the candidates for practical magnetic semiconductors with the high Curie temperature (T ). We have successfully prepared well-crystallized and epitaxial Fe Ti O films by using a reactive helicon plasma sputtering technique. The structural characterizations indicated that the films had the order structure (R over(3, -) symmetry), where Ti- and Fe-rich layers were stacked alternately along the c-axis, without any secondary phase. The subsequent annealing of the films in vacuum at 700 °C promoted the R over(3, -) symmetry. Only the films having the good R over(3, -) symmetry had large ferrimagnetic moments at room temperature. The resistivities of the films clearly showed semiconducting behavior, i.e., logarithmic resistivity showed a monotonous increase with increasing the inverse temperature. The minimum room temperature resistivity of the films was about 10 Ω cm. From the Hall effect measurement all films had n-type conduction. The carrier concentration was estimated to be about 10 -10 cm , depending on the annealing conditions. © 2006 Elsevier B.V. All rights reserved. 2-x x 3 C 1.4 0.6 3 -1 19 21 -3

DOI： 10.1016/j.jmmm.2006.10.783

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Synthesis, morphology and color tone properties of the lanthanum substituted hematite

T. I. Bhuiyan, M. Nakanishi, Y. Kusano, T. Fujii, J. Takada, Y. Ikeda

Materials Letters 61 ( 17 ) 3774 - 3777 2007

The polymeric complex method has been employed to investigate the effects of substitution by lanthanum into hematite powder on structures, morphology and color tone properties. X-ray diffraction measurements evidenced the existence of Fe La O at 1000 °C-1200 °C by shifting peaks to lower angles. At higher temperature, lattice parameters and cell volume were found to expand due to the incorporation of La ion into the hematite in the range 301.98-303.87 Å . Crystalline size decreased when increasing the amount of La ion in the reaction process. Suppression of particle growth was observed by the Field Emission Scanning Electron Microscopy studies at higher temperatures. Brighter yellowish-red color than that of pure hematite was obtained and it grew into deeper color tone rapidly by increasing the amount of La ion into the hematite. © 2007. 2 - x x 3 3+ 3 3+ 3+

DOI： 10.1016/j.matlet.2006.12.032

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Characteristics of hollow microtubes consisting of amorphous iron oxide nanoparticles produced by iron oxidizing bacteria, Leptothrix ochracea

H. Hashimoto, S. Yokoyama, H. Asaoka, Y. Kusano, Y. Ikeda, M. Seno, J. Takada, T. Fujii, M. Nakanishi, R. Murakami

Journal of Magnetism and Magnetic Materials 310 ( Issue 2 SUPPL. PART 3 ) 2405 - 2407 2007

Some features of characteristic iron oxide sheaths which the iron oxidizing bacteria Leptothrix ochracea (L. oceracea) formed were studied in order to make clear their morphology microstructure, chemical composition, and crystal structure through scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDX), and X-ray diffraction (XRD). Each sheath was a hollow tube with average outer and inner diameters of 1.1 and 1.4 μm, respectively. Their length ranged from 10 to 200 μm and the aspect ratio was 10-200. Each sheath was constructed by very small particles with a diameter of less than 100 nm. The hollow sheaths were mainly composed of Fe and O with small amounts of Si and P. The chemical composition analyzed by EDX was roughly Fe:Si:P=80:15:5 with the exception of O. XRD measurement revealed that crystal structures of the sheath were similar to that of 2-line ferrihydrite. The sheath showed spin-glass-like magnetic properties. © 2006 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.jmmm.2006.10.793

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Synthesis, structures and properties of the cerium doped hematite co-existing with CeO<inf>2</inf>

Tarequl Islam Bhuiyan, Makoto Nakanishi, Yoshihiro Kusano, Tatsuo Fujii, Jun Takada, Yasunori Ikeda

Funtai Oyobi Fummatsu Yakin/Journal of the Japan Society of Powder and Powder Metallurgy 54 ( 2 ) 112 - 118 2007

Cerium doped hematite powders obtained by polymeric complex method following the hydrolysis of FeCl · 6H O and Ce(NH ) (NO )6. X-ray diffraction pattern of cerium doped samples obtained at 1000°C̃ 1200°C for two hours in air revealed some solubility of cerium ion in α-Fe O over the composition range of 5%̃15 at% that were characterized by the shifting of X-ray diffraction peaks compared with the internal silicon standard. X-ray Photoelectron Spectra investigations revealed the existence of Ce ion at higher temperature. Unit cell parameters were found to expand due to the incorporation of cerium ions into the hematite lattice. Field Emission Scanning Electron Microscopy studies showed that the growth of particles was suppressed in the appearance of cerium ions into the α-Fe O lattice. Fe Ce O exhibits much lower magnetization due to the incorporation of non-magnetic cerium ions into the α-Fe O . Spectroscopy measurement evidenced that cerium doped hematite samples exhibited brighter yellowish red color tone than that of pure α-Fe O . 3 2 4 2 3 2 3 3+ 2 3 2-x x 3 2 3 2 3

DOI： 10.2497/jjspm.54.112

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Iodine intercalation and deintercalation of a Sr-free Bi-based cuprate: Bi<inf>2</inf>(La,Na)<inf>2</inf>CuO

Yoshiaki Tanaka, Makoto Nakanishi, Tatsuo Fujii, Jun Takada, Yoshihiro Kusano, Yasunori Ikeda

Ceramic Transactions 196 85 - 90 2006

Iodine intercalation and deintercalation of a Sr-free Bi-based cuprate, Bi (La,Na) CuO:, have been investigated. It has been confirmed by powder X-ray diffraction and thermogravimetric analysis that the stage-1 iodine-intercalated compound Bi (La,Na) CuO l with x=1.0 was formed. As in the case of a Bi (Sr,La) CuO: (Bi-2201) specimen, expansion of the c-length of the stage-1 iodine-intercalated compound was 3.6 Å, compared with one half that of host compound. After deintercalation of the intercalated iodine, the stage-1 iodine-intercalated compound returned reversibly to the host compound. The powder X-ray diffraction pattern showed the formation of the intermediate phase containing a certain amount of iodine, not assigned to the stage-2 intercalated compound, during the deintercalation. Neither host compound nor iodine-intercalated compound exhibited superconductivity down to 2 K. 2 2 2 2 7 x 2 2

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Preparation and characterization of epitaxial Fe2-xTi xO3 solid solution films

Fujii, T, Hashimoto, H, Takada, Y, Nakanishi, M, Takada, J

Ceramic Transactions 2006

Synthesis of Hexagonal Ferrites by Citric Complex Method

Takeyuki Kikuchi, Tatsuya Nakamura, Masamichi Miki, Makoto Nakanishi, Tatsuo Fujii, Jun Takada, Yasunori Ikeda

Advances in Science and Technology 2006

Preparation of Z-type hexagonal ferrite, Co<inf>2</inf>Z, using alkaline mali de method

Akira Sasaki, Makoto Nakanishi, Tatsuo Fujii, Jun Takada

Ceramic Transactions 196 497 - 503 2006

In this study, low temperature preparation conditions for Co Z (3BaO·2CoO·12Fe O ) particles were investigated by using alkaline halide method. The obtained particles were characterized by using X-ray diffraction and scanning electron microscopy techniques. Many factors such as the metal compositions, heating temperature, heating and cooling rates, and amount of flux reagents were changed for the preparation. The X-ray diffraction analysis indicated that (1) the metal compositions, (2) flux reagent, and (3) heating rate were important to obtain Co Z at low temperature using the alkaline halide method. Nearly monophasic Co Z was formed under the following conditions: metal compositional ratio of Ba : Co: Fe = 3.0 : 1.5 : 24 with 10wt% BaCl flux and rapid heating to 1200 °C for 6 hours. Co Z powders mixed with an EPDM rubber were pressed to a sheet form. The electromagnetic properties of rubber sheets were examined to apply to use as an electromagnetic wave absorber. 2 2 3 2 2 2 2

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Preparation and magnetic properties of Carbon/Fe-Co alloy composite by polymerized complex method

Yukiko Uchida, Kyoko Oishi, Makoto Nakanishi, Tatsuo Fujii, Jun Takada, Yoshihiro Kusano, Takeyuki Kikuchi

Funtai Oyobi Fummatsu Yakin/Journal of the Japan Society of Powder and Powder Metallurgy 52 ( 8 ) 640 - 645 2005.8

Language：Japanese

We have successfully prepared Carbon/Fe-Co alloy composites starting from metal organic precursors synthesized by polymerized complex method. The carbon/Fe-Co alloy composites were obtained after the carbonization of the precursors heat-treated at ambient pressure and lower temperatures ranging from 500 to 700°C in N 2 gas flow. Crystalline sizes of both carbon matrix and Fe-Co alloy particles were determined by X-ray diffraction measurements as a function of the Co concentration and the carbonized temperature. The alloy particles were widely dispersed in the carbon matrix and the particle size carbonized at 600°C was about 20-50nm observed by scanning electron microscopy. The composite carbonized at 600°C had very small coercivity of 14 Oe and exhibited relatively large permeability spectra at frequency of GHz range.

DOI： 10.2497/jjspm.52.640

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Preparation and magnetic properties of Carbon/Fe-Co alloy composite by polymerized complex method

Yukiko Uchida, Kyoko Oishi, Makoto Nakanishi, Tatsuo Fujii, Jun Takada, Yoshihiro Kusano, Takeyuki Kikuchi

Funtai Oyobi Fummatsu Yakin/Journal of the Japan Society of Powder and Powder Metallurgy 52 ( 8 ) 640 - 645 2005.8

Language：Japanese

DOI： 10.2497/jjspm.52.640

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Preparation and magnetic properties of the CoFe<inf>2</inf>O<inf>4</inf> thin films on Si substrate by sol-gel technique

Nimai Chand Pramanik, Tatsuo Fujii, Makoto Nakanishi, Jun Takada

Journal of Materials Science 40 ( 16 ) 4169 - 4172 2005

A stable precursor for CoFe O thin film was prepared by sol-gel technique from the aqueous solution of FeCl •6H O and CoCl •6H O. Sol was deposited on a naturally oxidized silicon-substrate by spinning technique (2000 rpm) and heat treated at different temperatures ranging from 700 to 1100°C. Thickness of the films was controlled in the range of 400-500 nm and all the films were characterized by using XRD and SEM. The effects of temperature and the composition on the formation of CoFe O thin film were also studied. Films obtained at relatively lower temperature showed multi-phases of α-Fe O , CoFe O and CoO while the formation of CoFe O phase increases with increasing temperature. Furthermore, the composition of the solution in mol% has great role on the formation of CoFe O films and the film containing 50 mol% of Co exhibited CoFe O mono-phase. Surface morphology of the films was studied by scanning electron microscope (SEM). Magnetic properties of the films, studied by using vibrating sample magnetometer (VSM), showed relatively high saturation magnetization (8.04-22.21 kWb/m ) as well as high coercivity (44.59-63.30 kA/m). Saturation magnetization also increases with increasing heat treatment temperature. © 2005 Springer Science + Business Media, Inc. 2 4 3 2 2 2 2 4 2 3 2 4 2 4 2 4 2 4 2+ 2

DOI： 10.1007/s10853-005-3819-1

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Magnetic and electronic properties of Fe<inf>1.2</inf>Ti <inf>0.8</inf>O<inf>3</inf>/Fe<inf>2</inf>O<inf>3</inf> bilayered films

Tatsuo Fujii, Yusuke Takada, Makoto Nakanishi, Jun Takada

INTERMAG ASIA 2005: Digests of the IEEE International Magnetics Conference 728 2005

Synthesis and characterization of cerium substituted hematite by sol-gel method

Nimai Chand Pramanik, Tarequl Islam Bhuiyan, Makoto Nakanishi, Tatsuo Fujii, Jun Takada, Sang Il Seok

Materials Letters 59 ( 28 ) 3783 - 3787 2005

Fine particles of cerium substituted hematite with different compositions were prepared by the sol-gel method from the aqueous solution of their corresponding metal salts. Mixed hydroxides of Fe and Ce were obtained by reacting aqueous NH with the aqueous solution of FeCl and Ce(NH ) (NO ) at pH 2.5-3.0) and they were heat treated at different temperatures between 400 and 1200°C in air for 2 h to get the mixed oxide product. Thermal analysis and X-ray diffraction studies revealed the coexistence of Fe O and CeO phase separately up to 900°C, and covalent interaction between them above 1000°C, which was evidenced by the shifting of the XRD peaks. Unit cell parameters and the cell volumes (V) of the samples derived between 1000 and 1200°C were found to be in the range a = 5.045-5.048 ± 0.007 Å, c = 13.774-13.815 ± 0.041 Å and V = 303.608-304.874 Å respectively. It was observed that both the lattice parameters and the cell volumes were higher than that of the pure α-Fe O (a = 5.036 Å, c = 13.749 Å, V = 301.976 Å ) system. The expansion of lattice parameters further supported the incorporation of the large Ce ion into the α-Fe O matrix. The lattice parameter increased with increasing Ce ion loading. FESEM studies showed the growth of the particles with increasing temperature though it was suppressed due to the presence of Ce ions as compared to the pure system. © 2005 Elsevier B.V. All rights reserved. 3+ 4+ 3 3 4+ 4+ 4+ 3 3 3 2 3 6 2 3 2 2 3 2 3

DOI： 10.1016/j.matlet.2005.06.056

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Development of Co<inf>1+x</inf>Fe<inf>2-x</inf>O<inf>4</inf> (x=0-0.5) thin films on SiO<inf>2</inf> glass by the sol-gel method and the study of the effect of composition on their magnetic properties

Nimai Chand Pramanik, Tatsuo Fujii, Makoto Nakanishi, Jun Takada

Materials Letters 59 ( 1 ) 88 - 93 2005

Spinel-type Co Fe O (x=0-0.5) thin films (∼450 nm thickness) on SiO glass substrate were prepared by the sol-gel method using spinning technique (2000 rpm) from the aqueous solution of FeCl .6H O and CoCl .6H O. All the films were heat treated at different temperatures ranging from 700 to 1100°C. The films were structurally characterized by using the X-ray diffraction technique (XRD), and the morphology was studied by field emission scanning electron microscope (FESEM). The effects of temperature and the composition ([Co ]/ [Fe ] ratio) on the formation of Co Fe O thin films were also studied. The films obtained at relatively low temperature showed mixed phases of α-Fe O , CoO, along with CoFe O , while the formation of the CoFe O phase increases with increasing temperature. Furthermore, the composition of the solution in terms of [Co ]/[Fe ] plays a great role on the formation and magnetic properties of the films. The magnetic properties of the films, studied using vibrating sample magnetometer (VSM), showed relatively small saturation magnetization, and coercivity was observed to be low as compared with that of other reports. Saturation magnetization also increases with increasing heat treatment temperature. © 2004 Elsevier B.V. All rights reserved. 1+x 2-x 4 2 3 2 2 2 1+x 2-x 4 2 3 2 4 2 4 2+ 3+ 2+ 3+

DOI： 10.1016/j.matlet.2004.09.023

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