Novel Route to Cubic Boron Nitride Dendritic Nanostructures under Electron Beam Irradiation

Yin, Longwei; Li, Musen; Liu, Yuxian; Xu, Bin; Sui, Jin-Ling; Qi, Yong‐Xin

doi:10.1002/adma.200304674

Cited by 17 publications

(5 citation statements)

References 19 publications

(18 reference statements)

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“…Many materials such as glass [6], polymers (i.e., polyvinyl alcohol) [7] and inorganic materials (i.e., clay, hexagonal boron nitride (hBN), and aluminum) [2] have been developed as CNT composites, exhibiting enhanced physical properties. Among these CNT composites, hBN/CNT composite materials have been scarcely studied, although hBN has excellent physical properties (e.g., high temperature stability, large thermal conductivity, low density, low dielectric constant, and high mechanical strength) [8,9]. In this study, hBN/CNT composite particles were synthesized using a gas-phase process.…”

Section: Introductionmentioning

confidence: 99%

Direct synthesis of hBN/MWCNT composite particles using spray pyrolysis

Iskandar

Kim

Nandiyanto

et al. 2009

Journal of Alloys and Compounds

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Section: Introductionmentioning

confidence: 99%

Direct synthesis of hBN/MWCNT composite particles using spray pyrolysis

Iskandar

Kim

Nandiyanto

et al. 2009

Journal of Alloys and Compounds

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“…A representative EEL spectrum corresponding to the nanorod in Figure a is shown in the inset to estimate the stoichiometry of the nanorods. The typical ionization edges at 190, 284, and 403 eV, corresponding to the characteristic K-shell ionization edges of B, C, and N, respectively. , The important result here is that the presence of a much weaker π-type peak for B and C from the nanorod compared to that of g-BC 2 N and the loss of sharp peak at 403, which is the feature for the N K-edge that can be attributed to an sp 2 -like crystalline system . All these indicate that the tetragonal phase possesses complicated bonding structures that are different from that of both cubic and graphite-like B-C-N phases.…”

Section: Resultsmentioning

confidence: 77%

“…16,17 The important result here is that the presence of a much weaker π-type peak for B and C from the nanorod compared to that of g-BC 2 N and the loss of sharp peak at 403, which is the feature for the N K-edge that can be attributed to an sp 2 -like crystalline system. 18 All these indicate that the tetragonal phase possesses complicated bonding structures that are different from that of both cubic and graphite-like B-C-N phases. Besides, a very small peak at 532 eV, the K-edge excitation of oxygen, was also found in EELS spectra.…”

Section: Resultsmentioning

confidence: 99%

Synthesis and First-Principles Studies of Single-Crystalline β-BC₂N with Oxygen-Bearing Defects

Hou

Gao

Gou

et al. 2008

Crystal Growth & Design

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Single-crystalline B-C-N nanorods were prepared at 500 °C and less than about 20 MPa. Results from X-ray powder diffraction (XRD) and selected-area electron diffraction (SAED) measurements suggest that the synthesized single-crystalline B-C-N is of tetragonal structure and its lattice constants are a ) 7.12(5) Å and c ) 3.57(3) Å. The nanorods all are very straight, and the ratios of length to diameter are between 5 and 30. High resolution transmission electron microscopy (HRTEM) and scanning electron microscopy (SEM) observations confirm the well-defined nanorods grown preferentially perpendicular to the [220] direction develop tetragonal morphologies. The energy-loss spectroscopy (EELS) and energy-dispersive X-ray (EDX) elemental mapping confirm that the nanorod is composed of B, C, N, and a trace of oxygen, and its stoichiometry is determined to be close to BC 2 N. First-principles calculations confirm that the as-prepared sample is superlattice phase of β-BC 2 N phase with defects of the C N ′ and the O N ′. In addition, it is a semiconductor material with a direct energy band gap 1.21 eV. The calculated hardness is comparable to that of diamond.

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“…In order to prepare cBN, many routes have been developed, for example, high temperature and high pressure (HTHP) method, chemical vapor deposition (CVD) method, physical vapor deposition (PVD) method, etc. [4][5][6][7][8][9][10][11][12][13] . Among them, HTHP route is the one that has been most intensively and extensively investigated.…”

mentioning

confidence: 99%

Investigation on the key factors in the hydrothermal synthesis of BN: The way of introducing sodium azide

Lian

Wang

et al. 2007

CHINESE SCI BULL

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The way of introducing sodium azide (NaN 3 ) into the reaction solution played an important role in the preparation of cBN by hydrothermal synthesis method. The results showed that both cBN content and crystalline perfection of the samples improved with increasing R N value, and pure cBN could be obtained at 300℃ and 10 MPa when R N increased to 3:1. Here R N is defined as R N =NaN 3 (I)/NaN 3 (II), where NaN 3 (I) denotes the amount of NaN 3 (in molar) that is added into the autoclave at the beginning of the reaction process, and NaN 3 (II) is the amount of NaN 3 (also in molar) introduced into the autoclave at high temperature and high pressure (i.e. 300℃ and 10 MPa). In order to explain the experimental results, a preliminary model was proposed in this paper.cubic boron nitride, hydrothermal synthesis, sodium azide Cubic boron nitride (cBN) is an ideal candidate for the fabrication of cutting tools, protective coatings and grinding materials, because of its excellent merits such as super-hardness, high thermal conductivity, and inertness against ferrous metals [1,2] . On the other hand, cBN bulk crystal is of great value in the fabrication of UV optoelectronic devices and detectors, high-power electronic devices, highly transparent windows for microwave equipment, etc. [3] . In order to prepare cBN, many routes have been developed, for example, high temperature and high pressure (HTHP) method, chemical vapor deposition (CVD) method, physical vapor deposition (PVD) method, etc. [4][5][6][7][8][9][10][11][12][13] . Among them, HTHP route is the one that has been most intensively and extensively investigated. However, rather harsh conditions, such as high temperature and high pressure are required in this route [14] . The CVD method has been successfully used for the deposition of cBN films, but the crystalline perfection still needs to be improved, and turbostratic BN and amorphous BN often co-exist with cBN. Moreover, large residual stresses also exist in the cBN film, which severely limits its applications [15,16] .In order to synthesize cBN under moderate conditions, and eventually grow bulk cBN crystals, we have ever developed hydrothermal and solvothermal synthesis routes. By using these routes, samples with high cBN content have been prepared. For example, Hao et al. [17][18][19] synthesized cBN nanocrystals at low temperature and low pressure by using benzene-thermal method, Yu et al. [20,21] synthesized nearly single-phase cBN from hydrothermal solution by using a phase-selective synthesis route. However, the effects of the key affecting factors have not been investigated. In order to synthesize single-phase cBN, and furthermore, grow bulk cBN crystals, it is necessary to intensively investigate the key factors and optimize the synthesis parameters. In this paper, the results of increasing cBN content by changing the way of introducing nitrogen source into the reaction

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Novel Route to Cubic Boron Nitride Dendritic Nanostructures under Electron Beam Irradiation

Cited by 17 publications

References 19 publications

Direct synthesis of hBN/MWCNT composite particles using spray pyrolysis

Direct synthesis of hBN/MWCNT composite particles using spray pyrolysis

Synthesis and First-Principles Studies of Single-Crystalline β-BC₂N with Oxygen-Bearing Defects

Investigation on the key factors in the hydrothermal synthesis of BN: The way of introducing sodium azide

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Novel Route to Cubic Boron Nitride Dendritic Nanostructures under Electron Beam Irradiation

Cited by 17 publications

References 19 publications

Direct synthesis of hBN/MWCNT composite particles using spray pyrolysis

Direct synthesis of hBN/MWCNT composite particles using spray pyrolysis

Synthesis and First-Principles Studies of Single-Crystalline β-BC2N with Oxygen-Bearing Defects

Investigation on the key factors in the hydrothermal synthesis of BN: The way of introducing sodium azide

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Synthesis and First-Principles Studies of Single-Crystalline β-BC₂N with Oxygen-Bearing Defects