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Journal Articles

Synthesis of hexagonal boron carbonitride without nitrogen void defects

Mannan, M. A.*; Baba, Yuji; Kida, Tetsuya*; Nagano, Masamitsu*; Noguchi, Hideyuki*

Materials Sciences and Applications, 6(5), p.353 - 359, 2015/05

The synthesis and structure of hexagonal boron carbonitride (h-BCN) film on polycrystalline diamond surface were reported. Polycrystalline diamond and/or diamond-like carbon were first fabricated on Si (100) and then it was used as substrate. The deposition was performed by radio frequency plasma enhanced chemical vapor deposition. In order to reduce the content of nitrogen void defects, the deposition was performed at the high temperature of 950$$^{circ}$$C under the working pressure of 2.6 Pa. The typical sample with atomic composition of B$$_{31}$$C$$_{37}$$N$$_{26}$$O$$_{6}$$ in the h-BCN lattice was characterized by X-ray photoelectron spectroscopy. The fine structure of the film was studied by near-edge X-ray absorption fine structure (NEXAFS) measurements. The B K-edge and N K-edge of NEXAFS spectra revealed that the synthesized h-BCN film has the ideal honeycomb-like BN$$_{3}$$ configuration without nitrogen void defects.

Journal Articles

Hexagonal nano-crystalline BCN films grown on Si (100) substrate studied by X-ray absorption spectroscopy

Mannan, M. A.*; Baba, Yuji; Hirao, Norie; Kida, Tetsuya*; Nagano, Masamitsu*; Noguchi, Hideyuki*

Materials Sciences and Applications, 4(5A), p.11 - 19, 2013/05

Hexagonal nano-crystalline boron carbonitride (h-BCN) films grown on Si (100) substrate have been investigated. The films were synthesized by radio frequency plasma enhanced chemical vapor deposition using tris-dimethylamino borane as a precursor. Formation of the nano-crystalline h-BCN compound has been confirmed by X-ray diffraction analysis. The films composed of B, C, and N atoms with different B-N, B-C, C-N chemical bonds in forming the sp2-BCN atomic configuration studied by X-ray photoelectron spectroscopy. Orientation and local structures of the h-BCN hybrid were studied by near-edge X-ray absorption fine structure (NEXAFS) measurements. The dominant presence of $$pi$$$$^{*}$$ and $$sigma$$$$^{*}$$ resonance peaks of the sp2-hybrid orbitals in the B K-edge NEXAFS spectra revealed the formation of the flat sp2-BCN configuration around B atoms which are bound with three nitrogen atoms.

Journal Articles

Orientation of one-dimensional silicon polymer films studied by X-ray absorption spectroscopy

Mannan, M. A.*; Baba, Yuji; Sekiguchi, Tetsuhiro; Shimoyama, Iwao; Hirao, Norie; Nagano, Masamitsu*; Noguchi, Hideyuki*

Journal of Nanomaterials, 2012, p.528256_1 - 528256_9, 2012/00

 Times Cited Count:0 Percentile:0(Nanoscience & Nanotechnology)

Molecular orientations for thin films of one-dimensional silicon polymers grown by vacuum evaporation have been assigned by X-ray absorption fine structure (XAFS) using linearly polarized synchrotron radiation. For XAFS spectra of polydimethlysilane (PDMS) films on highly oriented pyrolytic graphite (HOPG), the intensities of two peaks were found to be strongly polarization dependent. Quantitative evaluation of the polarization dependence of the XAFS spectra revealed that the polymers are oriented nearly parallel to the surface. The observed orientation is opposite to the previously observed results for PDMS on oxide (indium tin oxide) and metal (polycrystalline copper). The flat-lying feature of PDMS observed only on HOPG surface is attributed to the interaction between CH bonds in PDMS and $$pi$$ orbitals in HOPG surface.

Journal Articles

Orientation of one-dimensional silicon polymer films studied by polarization-dependent NEXAFS

Mannan, M. A.*; Baba, Yuji; Sekiguchi, Tetsuhiro; Shimoyama, Iwao; Hirao, Norie; Nagano, Masamitsu*; Noguchi, Hideyuki*

Photon Factory Activity Report 2011, Part B, P. 159, 2012/00

no abstracts in English

Journal Articles

Orientation of B-C-N hybrid films deposited on Ni (111) and polycrystalline Ti substrates explored by X-ray absorption spectroscopy

Mannan, M. A.; Baba, Yuji; Kida, Tetsuya*; Nagano, Masamitsu*; Shimoyama, Iwao; Hirao, Norie; Noguchi, Hideyuki*

Thin Solid Films, 519(6), p.1780 - 1786, 2011/01

 Times Cited Count:19 Percentile:61.3(Materials Science, Multidisciplinary)

Orientation of BCN hybrid films synthesized on Ni (111) and Ti substrates by radio frequency plasma enhanced chemical vapor deposition has been investigated. Formation of the $$sp$$$$^{2}$$-BCN hybrids was confirmed by X-ray diffraction. Raman spectra also suggested the presence of graphite-like $$sp$$$$^{2}$$-BCN hybrid bonds. Orientation and local structures of the films were studied by the near-edge X-ray absorption fine structure (NEXAFS) measurements using synchrotron radiation. The B K-edge NEXAFS spectra revealed the preferred formation of the $$sp$$$$^{2}$$-BCN hybrid configuration around the B atoms like-BN$$_{3}$$ on Ni (111). It was revealed that the BCN film is parallel to the surface on Ni(111). On the other hand, the film is randomly oriented on Ti surface. It was suggested that the chemical reactivity of the metal surface affects the orientation of the BCN hybrid film.

Journal Articles

Self-ordering of silicon polymer thin film grown on indium tin oxide surface investigated by X-ray absorption spectroscopy

Mannan, M. A.*; Baba, Yuji; Sekiguchi, Tetsuhiro; Shimoyama, Iwao; Hirao, Norie; Narita, Ayumi; Nagano, Masamitsu*; Noguchi, Hideyuki*

Journal of Electron Spectroscopy and Related Phenomena, 181(2-3), p.242 - 248, 2010/08

 Times Cited Count:5 Percentile:31.14(Spectroscopy)

The ordering and molecular orientation of polydimethylsilane (PDMS) films grown on indium tin oxide (ITO) surface has been assigned. The orientation of the samples as well as that of the annealed sample was studied by Si K-edge near-edge X-ray absorption fine structure (NEXAFS) and X-ray photoelectron spectroscopy using linearly polarized synchrotron radiation. The Si K-edge NEXAFS spectra for the thick film have at least four resonance peaks of which two peaks are found to be strongly polarization dependent. On the basis of the polarization dependences of the peak intensities, it is revealed that the backbones of the PDMS films are perpendicularly oriented on the ITO surface. The angle between surface and the Si-Si bonds for multilayered film calculated from the helical structure of PDMS molecule was found to be 41.5 $$^{circ}$$ which was almost coincided with the experimentally obtained angle of 40 $$^{circ}$$. It was concluded that PDMS molecules are highly self-ordered on ITO surface.

Journal Articles

Growth and characterization of stoichiometric BCN films on highly oriented pyrolytic graphite by radiofrequency plasma enhanced chemical vapor deposition

Mannan, M. A.; Noguchi, Hideyuki*; Kida, Tetsuya*; Nagano, Masamitsu*; Hirao, Norie; Baba, Yuji

Thin Solid Films, 518(15), p.4163 - 4169, 2010/05

 Times Cited Count:30 Percentile:73.92(Materials Science, Multidisciplinary)

Hexagonal boron carbonitride (h-BCN) hybrid films have been synthesized on highly oriented pyrolytic graphite by radiofrequency plasma enhanced chemical vapor deposition using tris-(dimethylamino)borane as a single-source molecular precursor. The films were characterized by X-ray photoelectron spectroscopy (XPS), near-edge X-ray absorption fine structure (NEXAFS) and Raman spectroscopic measurements. XPS measurement showed that the B atoms were bonded to C and N atoms to form the $$sp$$$$^{2}$$ BCN hybrid chemical environment. The atomic composition estimated from the XPS of the typical sample was found to be almost B1C1N1. NEXAFS spectra of the B K-edge and the N K-edge had the peaks due to the $$pi$$$$^{*}$$ and $$sigma$$$$^{*}$$ resonances of $$sp$$$$^{2}$$ hybrid orbitals implying the existence of the $$sp2$$ hybrid configurations of h-BCN around the B atoms.

Journal Articles

Distinct structural requirements for interleukin-4 (IL-4) and IL-13 binding to the shared IL-13 receptor facilitate cellular tuning of cytokine responsiveness

Ito, Takachika*; Suzuki, Shoichi*; Kanaji, Sachiko*; Shiraishi, Hiroshi*; Ota, Shoichiro*; Arima, Kazuhiko*; Tanaka, Go*; Tamada, Taro; Honjo, Eijiro*; Garcia, K. C.*; et al.

Journal of Biological Chemistry, 284(36), p.24289 - 24296, 2009/09

 Times Cited Count:23 Percentile:45.4(Biochemistry & Molecular Biology)

Both IL-4 and IL-13 can bind to the shared receptor composed of the IL-4 receptor $$alpha$$ chain and the IL-13 receptor $$alpha$$-1 chain (IL-13R$$alpha$$1); however, the assembly mechanisms of these ligands to the receptor is different, enabling the principal functions of these ligands to be different. We have previously shown that the N-terminal Ig-like domain in IL-13R$$alpha$$1, called the D1 domain, is the specific and critical binding unit for IL-13. However, it has still remained obscure which the amino acid has specific binding capacity to IL-13 and why the D1 domain acts as the binding site for IL-13, but not IL-4. To address these questions, in this study, we performed the mutational analyses for the D1 domain, combining the structural data to identify the amino acids critical for binding to IL-13. Mutations of Lys76, Lys77, or Ile78 in c' strand in which the crystal structure showed interact with IL-13 and those of Trp65 and Ala79 adjacent to the interacting site, resulted in significant impairment of IL-13 binding, demonstrating that these amino acids generate the binding site. Furthermore, mutations of Val35, Leu38, or Val42 at N-terminal $$beta$$-strand also resulted in loss of IL-13 binding, probably from decrease structural stability. None of the mutations employed here affected IL-4 binding. These results demonstrate that the hydrophobic patch composed of Lys76, Lys77, and Ile78 is the IL-13 recognition site and solidify our understanding that the differential requirements of the D1 domain in IL-13R$$alpha$$1 allows the shared receptor to respond differentially to IL-4 and IL-13.

Journal Articles

Synthesis of boron carbonitride (BCN) films by plasma-enhanced chemical vapor deposition using trimethylamine borane as a molecular precursor

Kida, Tetsuya*; Shigezumi, Kazuya*; Mannan, M. A.*; Akiyama, Morito*; Baba, Yuji; Nagano, Masamitsu*

Vacuum, 83(8), p.1143 - 1146, 2009/05

 Times Cited Count:15 Percentile:51.83(Materials Science, Multidisciplinary)

Boron carbonitride films were deposited on Si substrates by plasma-enhanced chemical vapor deposition using a powdered precursor of trimethylamine borane. The effect of using different carrier gasses and microwave powers was investigated. Field emission scanning electron microscopy revealed that the films have a nanofibrous structure with elongated features 20 nm in diameter and 200 nm in length. Fourier transfer infrared spectroscopy was used to investigate chemical bonding states present in the deposited films. The FT-IR results suggested that the films have multiple chemical bonding states including C-N, B-N, and B-C bonds, as well as oxygen incorporation in the form of B-O bonds. Mixing the powdered precursor with molecular sieve was found to reduce the oxygen content in the films by removing surface adsorbed water from the precursor.

Journal Articles

Atomic arrangement, composition and orientation of hexagonal BCN films synthesized by radiofrequency plasma enhanced CVD

Mannan, M. A.*; Kida, Tetsuya*; Noguchi, Hideyuki*; Nagano, Masamitsu*; Shimoyama, Iwao; Hirao, Norie; Baba, Yuji

Journal of the Ceramic Society of Japan, 117(1364), p.503 - 507, 2009/04

 Times Cited Count:11 Percentile:53.79(Materials Science, Ceramics)

Oriented hexagonal BCN films were synthesized on Si(100) substrate by radiofrequency plasma enhanced chemical vapor deposition using tris-(dimethylamino)borane as a precursor. The formation of the crystalline hexagonal BCN hybrids was confirmed by FT-IR and XRD. CH$$_{4}$$ + H$$_{2}$$ carrier gas increased the C content in the films in comparison with N$$_{2}$$ carrier gas. XPS measurement showed that the films were composed of a variety of B-N, B-C, C-N bonds to form the BCN atomic hybrids. The $$pi$$$$^{*}$$ resonance peak in the B K-edge NEXAFS spectra also indicated the presence of the ${it sp$^{2}$}$ hybrid configuration of B-C-N bonds like BN$$_{3}$$ in h-BN. The $$sigma$$$$^{*}$$ resonance peaks suggested the diversity in the $$sigma$$ bonds in the films. Orientation of the h-BCN hybrids was suggested on the basis of the polarization dependence of NEXAFS.

Journal Articles

Characterization of BCN films synthesized by radiofrequency plasma enhanced chemical vapor deposition

Mannan, M. A.*; Nagano, Masamitsu*; Kida, Tetsuya*; Hirao, Norie; Baba, Yuji

Journal of Physics and Chemistry of Solids, 70(1), p.20 - 25, 2009/01

 Times Cited Count:50 Percentile:83.99(Chemistry, Multidisciplinary)

Boron carbonitride (BCN) films have been synthesized on Si(100) substrate by radio frequency plasma enhanced chemical vapor deposition using Tris-(dimethylamino)borane (TDMAB) as a precursor. The formation of the sp$$^{2}$$-bonded BCN phase was confirmed by Fourier transform infrared spectroscopy. X-ray photoelectron spectroscopy measurements showed that B atoms were bonded to C and N atoms to form the BCN atomic hybrid configurations. Near-edge X-ray absorption fine structure measurements indicated that B atoms were bonded not only to N atoms but also to C atoms to form various configurations of sp$$^{2}$$-BCN atomic hybrids. The polarization-dependence of NEXAFS suggested that the predominant hybrid configuration of sp$$^{2}$$-BCN films oriented in the direction perpendicular to the Si substrate.

Journal Articles

Chemical bonding states and local structures of the oriented hexagonal BCN films synthesized by microwave plasma CVD

Mannan, M. A.; Noguchi, Hideyuki*; Kida, Tetsuya*; Nagano, Masamitsu*; Hirao, Norie; Baba, Yuji

Materials Science in Semiconductor Processing, 11(3), p.100 - 105, 2008/06

 Times Cited Count:24 Percentile:72.81(Engineering, Electrical & Electronic)

In order to synthesize oriented hexagonal boron carbonitride (h-BCN) films, borane-triethylamine complex was used as a single-source precursor. The films were deposited on Si(100) substrate by microwave plasma-enhanced chemical-vapor deposition using CH$$_{4}$$+H$$_{2}$$ as the carrier gas. Fourier transform infrared spectroscopy (FT-IR) confirmed the formation of hexagonal BCN phase in a short-range order. The chemical composition and the local structures of films were studied by X-ray photoelectron spectroscopy (XPS) and the near-edge X-ray absorption fine structure (NEXAFS) spectroscopic measurements. The NEXAFS measurement suggested that the B atoms are bonded not only to the N atoms but also to the C atoms to form various local structures of sp$$^{2}$$ B-C-N hybrid configurations. The polarization dependence of NEXAFS suggested that the local structures of the sp$$^{2}$$ BCN layers have different atomic orientations to the substrate.

Journal Articles

Hexagonal BCN films prepared by RF plasma-enhanced CVD

Mannan, M. A.*; Nagano, Masamitsu*; Hirao, Norie*; Baba, Yuji

Chemistry Letters, 37(1), p.96 - 97, 2008/01

 Times Cited Count:12 Percentile:43.74(Chemistry, Multidisciplinary)

Hexagonal boron carbonitride (h-BCN) films have been synthesized on silicon (100) substrate by radio frequency plasma enhanced chemical vapor deposition from tris(dimethylamino)-borane (TDMAB) as a precursor. X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy revealed that the film with a composition of B$$_{46}$$C$$_{18}$$N$$_{36}$$ had sp$$^{2}$$ B-C-N atomic hybridization. Near edge X-ray absorption fine structure suggested that the local structure of BCN showed different atomic orientation to the substrate.

Journal Articles

Characterization of boron carbonitride (BCN) thin films deposited by radiofrequency and microwave plasma enhanced chemical vapor deposition

Mannan, M. A.*; Nagano, Masamitsu*; Shigezumi, Kazuya*; Kida, Tetsuya*; Hirao, Norie*; Baba, Yuji

American Journal of Applied Sciences, 5(6), p.736 - 741, 2008/00

Boron carbonitride thin films with a thickness of 4 micrometer were synthesized on Si(100) substrate by radiofrequency and microwave plasma enhanced vapor deposition using trimethylamine boran as a precursor. It has bee observed that the films were adhered well to the silicon substrate even after being broken mechanically. X-ray diffraction (XRD) and filed emission scanning electron microscopy (FE-SEM) results showed that the films were amorphous and the surface was rough with inhomogeneous microstructure. On the basis of the X-ray photoelectron spectra (XPS), it was elucidated that B, C and N atoms have different chemical bonds such as B-N, B-C and C-N.

Journal Articles

Characterization of hexagonal boron carbonitride (h-BCN) films prepared by RF plasma enhanced CVD

Mannan, M. A.*; Nagano, Masamitsu*; Hirao, Norie*; Baba, Yuji

Proceedings of 24th Japan-Korea International Seminar on Ceramics, p.289 - 292, 2007/11

Boron carbonitride thin films were synthesized on Si(100) substrate by radiofrequency and microwave plasma enhanced vapor deposition using tris-dimethylamino borane as a precursor. The formation of the hexagonal phase of BCN films was confirmed by Fourier-transform infrared (FT-IR) spectroscopy. The measurements of X-ray photoelectron spectra (XPS) showed that boron atoms bonded to C and N atoms. The results for near edge X-ray absorption fine structures (NEXAFS) using synchrotron radiation supports the XPS results where B atoms bonded not only to nitrogen but also to carbon atoms to form various local structures. The polarization dependence of NEXAFS suggested that the local structures of BCN have different orientations in the films.

Journal Articles

Analysis of internal motions of interleukin-13 variant associated with severe bronchial asthma using $$^{15}$$N NMR relaxation measurements

Yoshida, Yuichiro*; Okuri, Takatoshi*; Takeda, Chika*; Kuroki, Ryota; Izuhara, Kenji*; Imoto, Taiji*; Ueda, Tadashi*

Biochemical and Biophysical Research Communications, 358(1), p.292 - 297, 2007/06

 Times Cited Count:4 Percentile:9.9(Biochemistry & Molecular Biology)

The single nucleotide polymorphism interleukin-13 (IL-13) R110Q is associated with severe bronchial asthma because its lower affinity leads to the augmentation of local IL-13 concentration, resulting in an increase in the signal transduction via IL-13R. Since the mutation site does not directly bind to IL-13 R$$alpha$$2, we carried out NMR relaxation analyses of the wild-type IL-13 and IL-13 R110Q in order to examine whether the R110Q mutation affects the internal motions in IL-13 molecules. The results showed that the internal motion in the micro- to millisecond time scale on helix D, which is suggested to be important for the interaction between IL-13 and IL-13R$$alpha$$2, is increased in IL-13-R110Q compared with that in the wild-type IL-13. It therefore appears that the difference in the internal motions on helix D between the wild-type IL-13 and IL-13-R110Q may be involved in their affinity differences with IL-13R$$alpha$$2.

Journal Articles

Plasma enhanced chemical vapor deposition of B-C-N films

Mannan, M. A.*; Kida, Tetsuya*; Nagano, Masamitsu*; Hirao, Norie*; Baba, Yuji

Advanced Ceramic Processing International, 3(1), p.51 - 54, 2006/11

B-C-N hybrid thin films were synthesized by plasma enhanced chemical vapor deposition using liquid organic molecules (tris-dimethylamine borane and trimethylamine borane) as molecular precursors. The Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy investigations suggest that the films are composed of hybridized boron, carbon and nitrogen atoms. The X-ray diffraction and field emission scanning electron microscopy investigations reveal that the films are almost amorphous and have micro-structure at 4.2-4.5 $$mu$$m. The micro-hardness of the as-deposited B-C-N films is found to be approximately 2-7 Gpa. It was concluded that the plasma enhanced chemical vapor deposition using the present organic molecules are suited for the synthesis of B-C-N hybrid thin films.

Oral presentation

Removal of long-lived minor actinides by means of solvent extraction with lipophilic chemically modified chitosan

Inoue, Katsutoshi*; Oto, Keisuke*; Yoshizuka, Kazuharu*; Naganawa, Hirochika; Tachimori, Shoichi*

no journal, , 

Lipophilic chitosan containing functional groups of dithiocarbamate (DTC-lipophilic chitosan) was prepared and tested for the selective solvent extraction of minor actinides (MA) from large excess of lanthanides in dilute nitric acid solution. This reagent was found to be soluble not only in chloroform and toluene but also in kerosene, which is very favorable for practical purposes. Although solid chitosan gel chemically modified with functional groups of dithiocarbamate prepared according to the conventional method had exhibited no selectivity to MA over lanthanides, DTC-lipophilic chitosan exhibited high selectivity to americium over europium; i.e., the separation factor of Am/Eu was as high as 1227 in the extraction at pH = 4. In addition, it exhibited the same separation factor at the second solvent extraction test carried out one week after the first test, suggesting that it is chemically stable at least for one week contrary to Cyanex 301 and DPTP.

Oral presentation

Chemical bonding states and local structures of BCN films prepared by RF plasma enhanced CVD

Mannan, M. A.*; Nagano, Masamitsu*; Hirao, Norie*; Baba, Yuji

no journal, , 

no abstracts in English

31 (Records 1-20 displayed on this page)