研究者詳細 - 難波　徳郎

論文 - 難波　徳郎

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Effect of bond valence sum on the structural modeling of lead borate glass 査読

Masaaki Nagao, Shinichi Sakida, Yasuhiko Benino, Tokuro Nanba, Atsushi Mukunoki, Tamotsu Chiba, Takahiro Kikuchi, Tomofumi Sakuragi, Hitoshi Owada

JOURNAL OF NON-CRYSTALLINE SOLIDS 592 2022年9月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ELSEVIER

The structural model of 66.7PbO-33.3B2O3 glass was constructed using a reverse Monte Carlo (RMC) method, in which bond valence sum (BVS) was added as a constraint condition to suppress formation of unrealistic local structures. Based on the crystal structures, the optimal BVS calculating conditions were determined. As a result, BVS distributions with small deviation were successfully achieved without lowering the reproducibility of other experimental constraints. The geometric asymmetry of PbOn polyhedra was evaluated from the eccentric dis-tance between Pb and gravity center of oxygen atoms. The average eccentric distance was shorter than that in the lead borate crystals, indicating less asymmetry of PbOn units in the RMC glass model. The connectivity between BOn and PbOn units was investigated. It was consequently concluded that the glass had a different network structure from the crystal with the same composition, which might be due to the different chemical bonding character between the lead borate glasses and crystals.

DOI： 10.1016/j.jnoncrysol.2022.121751

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Environmental activities on glass in Japan 招待査読

Tokuro Nanba, Yasuhiko Benino, Tomoko Akai

Journal of the Ceramic Society of Japan 130 ( 8 ) 605 - 610 2022年8月

Eco-Benign Orange-Hued Pigment Derived from Aluminum-Enriched Biogenous Iron Oxide Sheaths. 査読国際誌

Katsunori Tamura, Yuri Oshima, Yuta Fuse, Noriyuki Nagaoka, Tatsuki Kunoh, Makoto Nakanishi, Tatsuo Fujii, Tokuro Nanba, Jun Takada

ACS omega 7 ( 15 ) 12795 - 12802 2022年4月

記述言語：英語掲載種別：研究論文（学術雑誌）

Inorganic pigments have been widely used due to their low cost of production, strong hiding power, and chemical resistance; nevertheless, they have limited hue width and chromaticity. To eliminate these disadvantages, we herein propose the use of an ingenious biotemplate technique to produce Al-enriched biogenic iron oxide (BIOX) materials. Spectrophotometric color analysis showed that high levels of Al inclusion on heat-treated BIOX samples produced heightened yellowish hues and lightness. The Al-enriched BIOX sheaths exhibited a stable tubular structure and excellent thermal stability of color tones after heating at high temperatures and repetitive heat treatments. Ultrastructural analysis and mechanical destruction experiments revealed that the highly chromatic orange-hue of these pigments are ascribed probably to an ingenious cylindrical nanocomposite architecture composed of putative Fe-included low crystalline Al oxide regions and hematite particles embedded therein. The present work therefore demonstrates that the bioengineered material can serve as an epochal orange-hued inorganic pigment with low toxicity and marked thermostability that should meet large industrial demand.

DOI： 10.1021/acsomega.1c07390

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Structural analyses and reverse Monte Carlo modeling of niobium oxide amorphous film prepared by sputtering method 査読

Go Sajiki, Yasuhiko Benino, Chinatsu Oki, Koji Ohara, Hiroshi Okano, Tokuro Nanba

JOURNAL OF THE CERAMIC SOCIETY OF JAPAN 125 ( 10 ) 760 - 765 2017年10月

担当区分：最終著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：CERAMIC SOC JAPAN-NIPPON SERAMIKKUSU KYOKAI

Structural analyses of niobium oxide (NbOx) amorphous film prepared with a sputtering method have been performed by using synchrotron X-ray radiation at SPring-8. The composition was determined as Nb2O5 center dot 0.8H(2)O from the measurements of Rutherford back scattering, X-ray fluorescence, X-ray absorption near edge structure, and thermal desorption spectroscopy. Structural information was obtained by extended X-ray absorption fine structure and high energy X-ray diffraction measurements. It was supposed from the experimental data that NbOx consisted of distorted NbOn polyhedra connected by corner-and edge-sharing. Structural models were constructed with reverse Monte Carlo (RMC) simulations. In the RMC models, the structural characteristics were successfully reproduced, and H atoms were, however, randomly distributed. Then, bond valence sum (BVS) constraint was introduced to the RMC simulation. As the results, narrower distribution in BVS was achieved for all the constituent atoms, and distinct OH bonds were effectively generated in the RMC model. (C) 2017 The Ceramic Society of Japan. All rights reserved.

DOI： 10.2109/jcersj2.17053

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Investigation of electronic structure of amorphous niobium oxide based on the density functional theory calculation of crystalline niobium pentoxide polymorphs 査読

Chinatsu Oki, Go Sajiki, Shinichi Sakida, Yasuhiko Benino, Tokuro Nanba

JOURNAL OF THE CERAMIC SOCIETY OF JAPAN 124 ( 12 ) 1221 - 1225 2016年12月

担当区分：最終著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：CERAMIC SOC JAPAN-NIPPON SERAMIKKUSU KYOKAI

Electronic structure of amorphous niobium oxide prepared by a sputtering method was investigated based on optical absorption and photoelectron spectroscopies. In the valence band photoelectron spectra, broad peaks without any characteristic components were observed. Then, theoretical calculations based on a density functional theory were performed to interpret the experimental spectra by using three Nb2O5 polymorphs. Among the polymorphs, M-phase with tetragonal structure showed better reproducibility than the other B- and R-phases with monoclinic structure. It was finally concluded that the amorphous niobium oxide had a similar electronic structure to M-Nb2O5, and it was supposed that the broad feature in the photoelectron spectra was due to the broad distribution of Nb-O bonds in NbO6 polyhedra, which was characteristic in M-Nb2O5. (C) 2016 The Ceramic Society of Japan. All rights reserved.

DOI： 10.2109/jcersj2.16180

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Electrochemical and Photoelectrochemical Properties of Nano-Islands of Zinc and Niobium Oxides Deposited on Aluminum Thin Film by RF Magnetron Reactive Sputtering 査読

G. Sajiki, Y. Benino, T. Nanba, H. Okano

Materials Sciences and Applications 6 292 - 309 2015年

Nano-micrometer-architectural acidic silica prepared from iron oxide of leptothrix ochracea origin 査読

Hideki Hashimoto, Atsushi Itadani, Takayuki Kudoh, Satoshi Fukui, Yasushige Kuroda, Masaharu Seno, Yoshihiro Kusano, Yasunori Ikeda, Yasuhiko Benino, Tokuro Nanba, Makoto Nakanishi, Tatsuo Fujii, Jun Takada

ACS Applied Materials and Interfaces 5 ( 11 ) 5194 - 5200 2013年6月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：AMER CHEMICAL SOC

We prepared nano-micrometer-architectural acidic silica from a natural amorphous iron oxide with structural silicon which is a product of the iron-oxidizing bacterium Leptothrix ochracea. The starting material was heat-treated at 500 C in a H2 gas flow leading to segregation of α-Fe crystalline particles and then dissolved in 1 M hydrochloric acid to remove the α-Fe particles, giving a gray-colored precipitate. It was determined to be amorphous silica containing some amount of iron (Si/Fe = ∼60). The amorphous silica maintains the nano-microstructure of the starting material - ∼1-μm-diameter micrometer-tubules consisting of inner globular and outer fibrillar structures several tens of nanometer in size - and has many large pores which are most probably formed as a result of segregation of the α-Fe particles on the micrometer-tubule wall. The smallest particle size of the amorphous silica is ∼10 nm, and it has a large surface area of 550 m2/g with micropores (0.7 nm). By using pyridine vapor as a probe molecule to evaluate the active sites in the amorphous silica, we found that it has relatively strong Brønsted and Lewis acidic centers that do not desorb pyridine, even upon evacuation at 400 C. The acidity of this new silica material was confirmed through representative two catalytic reactions: ring-opening reaction and Friedel-Crafts-type reaction, both of which are known to require acid catalysts. © 2013 American Chemical Society.

DOI： 10.1021/am401029r

Distribution behavior of inorganic constituents in chemical recycling processes of a municipal waste slag 査読

Kohei Omura, Shinichi Sakida, Yasuhiko Benino, Tokuro Nanba

Journal of Asian Ceramic Societies 1 ( 1 ) 108 - 113 2013年

担当区分：最終著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Elsevier B.V.

A chemical recycling process of inorganic wastes has been developed, where after vitrifying wastes, the glasses were heat-treated and soaked in an acid, obtaining colorless and transparent SiO2-abundant glasses. In the present study, distribution behavior of the constituents such as Si, P, Ti, Al and so on present in a municipal waste slag was examined. According to compositional analyses, the recovered solids after acid treatment consisted of SiO2, P2O5 and TiO2, suggesting the preferential distribution of P and Ti atoms into SiO2-rich phase during phase separation. In high resolution microscopic analyses, however, it was observed that P and Ti atoms were distributed separately from Si atoms, and they were present in the different particles insoluble in the acid. It was finally concluded that the insoluble solids were produced by a dissolution-reprecipitation process, that is, once all the constituents of the vitrified slag were dissolved in the acid, P2O5 and TiO2 coprecipitated as particles, and TiO2 was indispensable for the precipitation of P2O5. SiO2 also precipitated as particles separately from P- and Ti-containing particles. © 2013 The Ceramic Society of Japan and the Korean Ceramic Society.

DOI： 10.1016/j.jascer.2013.03.003

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Preparation, microstructure, and color tone of microtubule material composed of hematite/amorphous-silicate nanocomposite from iron oxide of bacterial origin 査読

Hideki Hashimoto, Hiroshi Asaoka, Takuya Nakano, Yoshihiro Kusano, Hiromichi Ishihara, Yasunori Ikeda, Makoto Nakanishi, Tatsuo Fujii, Tadanori Yokoyama, Nanao Horiishi, Tokuro Nanba, Jun Takada

DYES AND PIGMENTS 95 ( 3 ) 639 - 643 2012年12月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ELSEVIER SCI LTD

By heating an amorphous iron oxide produced by Leptothrix ochracea, an iron-oxidizing bacterium species, at 600-1100 degrees C in air for 2 h, vivid red-colored powdered materials including alpha-Fe2O3 (hematite) and amorphous silicate with high thermostability were prepared which offer potential for use as over-glaze enamels on porcelain. The precise color tone of the materials greatly depends on the heat-treatment temperature. The most strikingly beautiful sample, heat-treated at 800 degrees C, is light yellowish-red in color (L* = 47.3, a* = 34.1, and b* = 34.6), has a unique microstructure, and does not fade in color even with reheating at 800 degrees C, which is the firing temperature for over-glaze enamel on porcelain. The sample primarily consists of crystalline hematite particles similar to 40 nm in diameter with slightly longer axis unit-cell parameters than those of pure hematite. The particles are covered with amorphous silicate phase similar to 5 nm in thickness and are intricately interconnected into microtubules with an average diameter of 1.26 mu m. The attractive color of this material is due to the following structural features: small particle size (similar to 40 nm). nanocomposite of hematite and amorphous silicate, and a microtubule structure that inhibits aggregation of individual hematite particles and microtubules. (C) 2012 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.dyepig.2012.06.024

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Amorphous structure of iron oxide of bacterial origin 査読

Hideki Hashimoto, Tatsuo Fujii, Shinji Kohara, Hiroshi Asaoka, Yoshihiro Kusano, Yasunori Ikeda, Makoto Nakanishi, Yasuhiko Benino, Tokuro Nanba, Jun Takada

MATERIALS CHEMISTRY AND PHYSICS 137 ( 2 ) 571 - 575 2012年12月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ELSEVIER SCIENCE SA

In nature, there are various iron oxides produced by the water-habitant bacterial group called "iron-oxidizing bacteria". These iron oxides have been studied mainly from biological and geochemical perspectives. Today, attempts are made to use such iron oxides as novel functional materials in several applications. However, their quantitative structural characteristics are still unclear. We studied the structure of iron oxide of microtubular form consisting of amorphous nanoparticles formed by an iron-oxidizing bacterium, Leptothrix ochracea, using a combination of high-energy X-ray diffraction and reverse Monte Carlo simulation. We found that its structure consists of a framework of corner- and edge-sharing distorted FeO6 octahedral units, while SiO4 tetrahedral units are isolated in the framework. The results reveal the atomic arrangement of iron oxide of bacterial origin, which is essential for investigating its potential as a functional material. (C) 2012 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.matchemphys.2012.10.002

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Effect of additives on the distribution of phosphorus associated with phase separation of borosilicate glasses 査読

Yasuhiko Benino, Yuki Ohtsuki, Shinichi Sakida, Tokuro Nanba

JOURNAL OF THE CERAMIC SOCIETY OF JAPAN 120 ( 1407 ) 490 - 493 2012年11月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：CERAMIC SOC JAPAN-NIPPON SERAMIKKUSU KYOKAI

Sodium borosilicate glasses containing phosphorus were prepared, and the effect of Al2O3 and TiO2 addition on the distribution behavior of phosphorus atoms associated with the phase separation was investigated. After heat treatment, a phase separation by the spinodal decomposition was commonly confirmed by SEM observation. In the additive-free sample, phosphorus was preferentially distributed into B2O3-rich phase after the phase separation, and after adding Al2O3 or TiO2, the amount of phosphorus distributed into SiO2-rich phase increased. It was also suggested that TiO2 had a stronger influence on the phosphorus distribution into SiO2-rich phase than Al2O3. P-31 MAS-NMR revealed that most of phosphorus atoms in the additive-free glass were present in PO4 units consisting of two terminal oxide ions, and the terminal oxide ions decreased and increased after the additions of Al2O3 and TiO2, respectively. It was suggested that this structural change brought about a change in the distribution of phosphorus. (C) 2012 The Ceramic Society of Japan. All rights reserved.

DOI： 10.2109/jcersj2.120.490

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Effect of Nb2O5 addition to SnO-P2O5 glass 査読

Satoshi Fukui, Shinichi Sakida, Yasuhiko Benino, Tokuro Nanba

JOURNAL OF THE CERAMIC SOCIETY OF JAPAN 120 ( 1407 ) 530 - 533 2012年11月

担当区分：責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：CERAMIC SOC JAPAN-NIPPON SERAMIKKUSU KYOKAI

SnO-P2O5 glasses have high refractive index and low glass transition temperature but have poor water durability. To improve water durability, NbO2.5 was added to SnO-P2O5 glasses, preparing SnO-NbO2.5-P2O5 glass. It was found that addition of only 4 mol % NbO2.5 was enough to achieve significant improvement of water durability, and at the same time, no degradation in thermal and optical properties was observed. (C)2012 The Ceramic Society of Japan. All rights reserved.

DOI： 10.2109/jcersj2.120.530

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Surface crystallization of stoichiometric glass with Bi2ZnB2O7 crystal using ultrasonic surface treatment followed by heat treatment 査読

Keita Kanenishi, Shinichi Sakida, Yasuhiko Benino, Tokuro Nanba

JOURNAL OF THE CERAMIC SOCIETY OF JAPAN 120 ( 1407 ) 509 - 512 2012年11月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：CERAMIC SOC JAPAN-NIPPON SERAMIKKUSU KYOKAI

Surface crystallized glass-ceramics with nonlinear optical Bi2ZnB2O7 (BZB) crystals were prepared by ultrasonic surface treatment (UST) followed by crystallization heat treatment for stoichiometric glass with a composition of 33.3Bi(2)O(3)-33.3ZnO-33.3B(2)O(3). According to the surface XRD measurements and microscopic observations, UST technique was found to be quite effective for lower temperature precipitation of BZB, indicating the ability of crystallization control of the target phase, such as phase selectivity, small size of precipitates, high orientation and their morphology. After the optimization of the process condition parameters for improving transparency and suppressing deformation of the sample, the effective optical nonlinearity of the transparent surface crystallized glass-ceramics was estimated as 0.7 pm/V. (C)2012 The Ceramic Society of Japan. All sights reserved.

DOI： 10.2109/jcersj2.120.509

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Prediction of glass structure by using multiple regression analysis 査読

Kumiko Ishii, Toru Tsuneoka, Shinichi Sakida, Yasuhiko Benino, Tokuro Nanba

JOURNAL OF THE CERAMIC SOCIETY OF JAPAN 120 ( 1399 ) 98 - 103 2012年3月

担当区分：責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：CERAMIC SOC JAPAN-NIPPON SERAMIKKUSU KYOKAI

Multiple regression analyses were applied to the prediction of glass structures, such as O 1s binding energy and fraction of fourfold coordinated boron atoms, N-4. In the case of linear combination of the content of glass constituents, an acceptable prediction accuracy was obtained for O 1s binding energy, and as for N-4, however, a poor agreement was observed between the prediction and measurement. After introducing quadratic and cubic interaction terms into the regression formula, a drastic improvement was achieved in the prediction of N-4. Some regression coefficients were dependent on basicity of each glass constituent, suggesting the feasibility of prediction for the glasses containing novel constituents whose regression parameters have never been determined. (C)2012 The Ceramic Society of Japan. All rights reserved.

DOI： 10.2109/jcersj2.120.98

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Fabrication and characterization of Er3+-doped tellurite glass Waveguides By Ag+-Na+ Ion-exchange Method Using a Dry Electromigration Process 査読

S. Sakida, K. Kimura, Y. Benino, T. Nanba

Processing, Properties, and Applications of Glass and Optical Materials: Ceramic Transactions 231 201 - 207 2012年

Functional and Structural Characterizations of Fresnoite Glass-Ceramics Oriented with UST Technique 査読

Y. Benino, A. Endo, S. Sakida, T. Nanba

Processing, Properties, and Applications of Glass and Optical Materials: Ceramic Transactions 231 161 - 165 2012年

Effect of TiO2 Addition on the Distribution of Phosphorus Associated with Phase Separation of Borosilicate Glasses 査読

Y. Ohtsuki, S. Sakida, Y. Benino, T. Nanba

Processing, Properties, and Applications of Glass and Optical Materials: Ceramic Transactions 231 145 - 149 2012年

Functional and structural characterizations of fresnoite glass-ceramics oriented with usttechnique

Y. Benino, A. Endo, S. Sakida, T. Nanba

Ceramic Transactions 231 161 - 165 2012年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：American Ceramic Society

Transparent glass ceramics with highly oriented surface crystalline layers of fresnoite Ba2TiSi2O8 were prepared by heat treatment of precursor glasses in BaO-TiO2-SiO2 system. The orientation along c-axis of fresnoite crystals normal to the glass surface was evaluated by the surface XRD patterns, and it was remarkably enhanced by ultrasonic surface treatment (UST) before the crystallization using fresnoite powder suspension in water. The effect of UST disappeared after heat treatment in the glass transition region, and the mechanism of UST was discussed on the basis of the persistence at elevated temperatures.

DOI： 10.1002/9781118472590.ch18

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Characterization of glasses based on basicity 招待査読

Tokuro Nanba

JOURNAL OF THE CERAMIC SOCIETY OF JAPAN 119 ( 1394 ) 720 - 725 2011年10月

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：CERAMIC SOC JAPAN-NIPPON SERAMIKKUSU KYOKAI

Basicity is defined as an electron donating ability of a material, and hence, an oxide material containing oxide ions with high electron density is regarded to be in high basicity. It has been demonstrated that basicity can be evaluated by binding energy of core level electrons, which is measured by X-ray photoelectron spectroscopy. Based on the experimental results obtained from a large number of oxide glasses, correlations among basicity, O1s binding energy, structure and properties of glasses have been investigated. In the present paper, some of the research outcomes are introduced. (C)2011 The Ceramic Society of Japan. All rights reserved.

DOI： 10.2109/jcersj2.119.720

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MgO-Al2O3スピネルの耐スラグ侵食性に及ぼすZrO2添加効果査読

藤田基成, 北基, 伊賀棒公一, 崎田真一, 紅野安彦, 難波徳郎, 三浦嘉也, 山口明良

耐火物 63 ( 6 ) 279 - 286 2011年6月

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