e-Journal of Surface Science and Nanotechnology
Online ISSN : 1348-0391
ISSN-L : 1348-0391
Regular Papers
  • Afif Hamzens, Ridho Kurniawan, Damar Rastri Adhika, Widayani, Ahmad ...
    原稿種別: Regular Paper
    専門分野: Nano-Materials
    2021 年 19 巻 p. 1-8
    発行日: 2021/02/27
    公開日: 2021/02/27
    ジャーナル オープンアクセス

    A near-infrared (NIR) reflector in cotton clothes may prevents several dermatological problems. TiO2 is commonly used for the NIR reflector coating in cotton. The NIR reflectance value is expected to increase if smaller TiO2 particles were used. A simple mechanical process of ultrasonic wet-milling to reduce the TiO2 particle size is proposed in this study. The reduction process utilizes ultrasonic cavitation by an ultrasonic homogenizer has succeeded in reducing the particle size from 170 to 80 nm as indicated by particle size measurement results and as supported by transmission electron microscopy results. The wet-milling particles of 80 nm TiO2, along with 170 and 280 nm TiO2, were used to coat cotton fabrics. Optimization of the coating process was performed using citric acid and chitosan as binder agents. The effect of citric acid and chitosan was studied through NIR spectroscopy, scanning electron microscopy, and X-ray fluorescence. From the NIR spectroscopy characterization results, it is found that the fabrics which are coated with the smallest TiO2 particle size (80 nm) indeed show highest NIR reflectance among others.

  • Atabek E. Atamuratov, Mahkam M. Khalilloev, Ahmed Yusupov, Jean Chambe ...
    原稿種別: Regular Paper
    専門分野: Devices and Sensors
    2021 年 19 巻 p. 9-12
    発行日: 2021/03/04
    公開日: 2021/03/04
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    The influence of the channel shape in a junctionless silicon- on-insulator finned field-effect transistor (JL SOI FinFET) on the amplitude of random telegraph noise (RTN) induced by single interface trapped charge has been simulated for the transistors with rectangular, trapezoidal, and triangular fin cross sections. The simulation of the RTN amplitude distribution along the channel induced by a single charge trapped at interface defect located at the fin top and at sidewall of JL SOI FinFETs with channels of different shapes is considered. It is established that at trapping the single charge at sidewall surface of the channel, the lowest RTN amplitude is seen for the triangular cross-section and the highest for the rectangular and trapezoidal cross-sections. At the single charge trapping at the top surface of the channel, the RTN amplitude is higher for the rectangle than for the trapezoidal cross-section.

  • Sohei Nakatsuka, Taishi Imaizumi, Tadashi Abukawa, Azusa N. Hattori, H ...
    原稿種別: Regular Paper
    専門分野: Micro- and Nano-Fabrication
    2021 年 19 巻 p. 13-19
    発行日: 2021/03/06
    公開日: 2021/03/06
    ジャーナル オープンアクセス

    Spatially arranged surfaces on the micro-rod structure, which was three-dimensionally (3D) architected on a Si(110) substrate have been thoroughly investigated by a system with micro-beam reflection high-energy electron diffraction (μ-RHEED) and scanning electron microscopy (SEM). The combination of μ-RHEED and SEM realized analytical structure investigation of 3D surfaces with the spatial resolution of sub micrometer for the 3D rectangular shaped rod consisting of a (110) top surface (20 μm wide) and {111} vertical side surfaces (10 μm wide). Exhaustive mapping revealed the peculiar reconstructed surface structures: Si(110) “16 × 2” single domain and {35 47 7} facet surfaces locally appeared on the interconnected edge region on the 3D structure in addition to the “16 × 2” and 7 × 7 super structures on flat top (110) and side {111} surfaces, respectively. The formation mechanism for “16 × 2” single-domain structure near the corner edge of the (110) surfaces and {35 47 7} facets on the corner edges between (110) and {111} surfaces were discussed from the viewpoint of the surface stability on the 3D geometrical shaped Si structure.

  • M. Okawa, K. Akikubo, S. Yamamoto, I. Matsuda, T. Saitoh
    原稿種別: Regular Paper
    専門分野: Electronic Properties
    2021 年 19 巻 p. 20-23
    発行日: 2021/03/18
    公開日: 2021/03/18
    ジャーナル オープンアクセス

    Temporal variations of valence states of the α-YbAl1−xFexB4 crystals (x = 0, 0.013, and 0.098) are experimentally examined in a nanosecond time-scale by time-resolved photoemission experiments using synchrotron radiation. The Yb 4f spectral features show no apparent change with time during relaxations after the optical pumping. The present experimental result indicates that dynamics of valence fluctuations in the material are likely dominated by a picosecond or much faster time-scale. The time-resolved measurement at the time-resolution limit at synchrotron radiation captured the trace of valence fluctuations.

  • Zeyang Xue, Yajing Mao, Chunhu Yu, Mingchang Wang, Chuangang Fan, Lizh ...
    原稿種別: Regular Paper
    専門分野: Catalysis
    2021 年 19 巻 p. 24-31
    発行日: 2021/04/03
    公開日: 2021/04/03
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    Bismuth oxide/indium oxide microspheres have been synthesized by a facile ethylenediaminetetraacetic acid (EDTA)-assisted hydrothermal process using sodium bismuthate and indium nitrate as raw materials. The obtained products were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), and solid ultraviolet-visible diffusion reflectance spectroscopy. XRD and SEM observations show that the obtained microspheres consist of tetragonal Bi2O3 and cubic In2O3 phases with a smooth surface and diameters between 150 nm and 1 μm. EDTA, hydrothermal temperature, and reaction time play essential roles in the formation of the bismuth oxide/indium oxide microspheres. The tetragonal Bi2O3 and cubic In2O3 phases are formed with increasing the hydrothermal temperature and the reaction time. Photocatalytic performance of the bismuth oxide/indium oxide microspheres was evaluated by photocatalytic degradation of rhodamine B in an aqueous solution with solar light irradiation. A rhodamine B degradation ratio depends on the solar light irradiation time and the microspheres dosage. Rhodamine B with 10 mg L−1 can be entirely removed by more than 10 mg of the bismuth oxide/indium oxide microspheres in the 10 mL aqueous solution under solar light irradiation for 6 h.

  • Juniarto M Palilu, Bambang Soegijono, Bonar T H Marbun
    原稿種別: Regular Paper
    専門分野: Structure
    2021 年 19 巻 p. 32-41
    発行日: 2021/04/22
    公開日: 2021/04/22
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    Portland cement slurries have undergone degradation due to carbonation-induced corrosion in contact with a CO2-rich environment. Many studies have observed degradation such as a decrease in the mechanical strength and an increase of permeability and porosity. When utilized in wells as a zonal isolation material in the CO2-rich environment, such degradation can be worsen by hydration shrinkage of Portland cement, in which micro-annuli are formed and, thus, effective permeability is increased. In this work, CaO was employed as an expansive additive admixed with Portland cement. The samples were hydrated for 1 and 7 days prior to carbonation for 14 days in an autoclave to simulate shorter and longer hydration times before contacted with a CO2-rich environment. Before carbonated in the autoclave, the samples were analyzed by X-ray diffraction. The expansion of the hydrated slurries was also observed for the first 24 h of hydration. After carbonation, the percentage of the corroded area was calculated, and a three-point bending test was conducted. The result shows that the CaO additive below 15% by weight of cement in the Portland cement slurry can enhance the slurry resistance against corrosion encroachment induced by the carbonation process. The presence of the CaO additive in the Portland cement slurry can mitigate the severe detrimental effect induced by carbonation.

Technical Notes
  • Seiji Makita, Hiroyuki Matsuda, Yasuaki Okano, Takayuki Yano, Eiken Na ...
    原稿種別: Regular Paper
    専門分野: Instrumentations and Techniques
    2021 年 19 巻 p. 42-47
    発行日: 2021/05/13
    公開日: 2021/05/13
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    The contrast of a photoelectron microscopy image depends on the type of excitation photon source and the photoelectron kinetic energy. The contrast inversion observed in the photoelectron image by Hg lamp excitation is due to differences in work functions specific to materials and surface conditions, and the contrast inversion in the case of vacuum ultraviolet light excitation is due to the difference in the valence band density of states. The mechanism of contrast formation in valence photoelectron images is well understood qualitatively as described above, but quantitative evaluations are required for accurate understanding. We investigated the photoelectron image contrast of gold checkerboard pattern printed on the silicon wafer. The intensity of the gold region near the Fermi level is higher than that of the silicon substrate region, while the inverted contrast images were obtained at lower kinetic energies. We found that in the case of core and valence photoelectrons, certain contamination degrades the image quality, but in the case of Hg lamp excitation, it increases signal intensity owing to the lowering of work function.