Journal of the Ceramic Society of Japan
Online ISSN : 1348-6535
Print ISSN : 1882-0743
ISSN-L : 1348-6535
Volume 120, Issue 1407
(November)
Displaying 1-20 of 20 articles from this issue
Feature: Advanced Ceramic Science and Technology in the Western Pacific Rim Area: Reviews
  • Fuji FUNABIKI, Toshio KAMIYA, Hideo HOSONO
    2012 Volume 120 Issue 1407 Pages 447-457
    Published: November 01, 2012
    Released on J-STAGE: November 01, 2012
    JOURNAL FREE ACCESS
    Impurity doping of crystalline Si is one of the most striking techniques in semiconductor technology. A rigid and perfect crystalline lattice is prerequisite for effective doping. However, it has been reported to date that introducing a small amount of impurities drastically improves also the properties of amorphous materials. This paper reviews three pronounced doping effects on optical and electrical properties of amorphous oxides; i.e., (i) F-doping of silica glass to improve the vacuum-ultraviolet optical transmission and radiation toughness, (ii) codoping effects on solubility enhancement of rare earth ions in silica glass melt, and (iii) electron-carrier generation in transparent amorphous oxide semiconductors. It is emphasized that effectiveness of electron doping is determined by the magnitude of electron affinity and stabilization energy of a dopant. Importance of the local structure formed around a dopant ion and the location of conduction band minimum measured from the vacuum level is addressed to understand the doping effects in amorphous oxides.
    Download PDF (3963K)
  • Yu TENG, Kaniyarakkal SHARAFUDEEN, Shifeng ZHOU, Jianrong QIU
    2012 Volume 120 Issue 1407 Pages 458-466
    Published: November 01, 2012
    Released on J-STAGE: November 01, 2012
    JOURNAL FREE ACCESS
    In the past decades, glass-ceramics embedded with nanocrystals have been proved to be one kind of the most promising photonic materials for applications in optical amplifiers, tunable solid-state lasers, luminescent solar concentrators and up-conversion luminescence devices, etc. Transition metal ions and rare-earth ions singly or co-doped glass-ceramics with excellent optical properties have been developed in laboratories, and some have achieved industrialization. In this review, we highlight our recent research achievements on the design and control of the optical properties of transition metal ions and rare-earth ions doped glass-ceramics etc. The important properties such as multicolor luminescence, broadband near-infrared emission and optical amplification are discussed. These studies are not only helpful for understanding the optical properties of active luminescent centers doped glass-ceramics, but also valuable for the fabrication of optical devices.
    Download PDF (3753K)
Feature: Advanced Ceramic Science and Technology in the Western Pacific Rim Area: Papers
  • Dong-Yeol YANG, Duk Yong YOON, Suk-Joong L. KANG
    2012 Volume 120 Issue 1407 Pages 467-472
    Published: November 01, 2012
    Released on J-STAGE: November 01, 2012
    JOURNAL FREE ACCESS
    Widely employed in the fabrication of structural ceramics, ball-milling is a process of mixing or pulverizing powders. Despite its popular use, the effects of ball-milling on grain growth behavior are nevertheless still obscure. In this study, we investigated the effects of ball-milling on grain growth behavior in light of the crystal growth theory in a model NbC–Co system with partially faceted grains. Two kinds of 90NbC–10Co (wt %) samples, with and without ball-milling, were prepared. With ball-milling, the density of dislocations increased considerably. In samples without ball-milling, abnormal grain growth (AGG) occurred from the beginning of liquid phase sintering at 1450°C. In contrast, in samples with ball-milling, grain growth behavior was quite normal and large abnormal grains did not appear up to 96 h of sintering. These observations can be explained in terms of the change in the critical driving force for appreciable growth with dislocation density. The present results also demonstrate that proper mechanical treatment (ball-milling) can be useful for suppressing AGG in cemented carbide systems.
    Download PDF (3613K)
  • Takeo SASAKI, Naoya SHIBATA, Katsuyuki MATSUNAGA, Takahisa YAMAMOTO, Y ...
    2012 Volume 120 Issue 1407 Pages 473-477
    Published: November 01, 2012
    Released on J-STAGE: November 01, 2012
    JOURNAL FREE ACCESS
    TEM in-situ indentation experiments were applied to directly observe the atomic structures on the cleavage planes of sapphire, and the structures were determined by HRTEM image simulation. It was found that cracks mainly propagate along the low index planes of sapphire, forming the atomic scale steps on the cleavage planes, and the atomic structures are dependent on the crystal orientation. In addition, the surface structures of the cleavage planes were found to be reconstructed in the vicinity of the respective surfaces. For the (1120) cleavage plane, the surface is composed of Al–O–Al cluster to form the complicated and metastable Al rich surface.
    Download PDF (3223K)
  • Kenji SHIDA, Yusuke OHARA, Motohide MATSUDA, Yoko SUYAMA
    2012 Volume 120 Issue 1407 Pages 478-482
    Published: November 01, 2012
    Released on J-STAGE: November 01, 2012
    JOURNAL FREE ACCESS
    Yttria-stabilized zirconia (YSZ) fibers various widths ranging from 36 to 66 µm of width were prepared by a drying process at 363 K from a zirconia sol containing 4 mol % yttria with 40 nm of primary particle size. The effects of preparation method on the crystal phase, microstructure and electrical properties of the obtained YSZ fibers were investigated. The obtained fibers were heat-treated at 1473 K for 1 h. The grain size and relative density of the fiber were 126 nm and 97%, respectively. The oxygen ion conductivity of the fiber showed heat-treated at 1473 K is 0.18 S/cm at 1273 K, which is the same as 8 YSZ bulk ceramics.
    Download PDF (3019K)
  • Naoki YAMAMOTO, Toshihiro ISOBE, Sachiko MATSUSHITA, Akira NAKAJIMA
    2012 Volume 120 Issue 1407 Pages 483-489
    Published: November 01, 2012
    Released on J-STAGE: November 01, 2012
    JOURNAL FREE ACCESS
    The influences of drying temperature on the crystallinity and specific surface area of TiO2 (rutile) powders prepared from acid treatments of BaTiO3 were investigated. Then, Cu was grafted onto the obtained powders using two sources: CuCl2 and (CH3COO)2Cu (CuAc2). The resultant powders were bundle-like rutile nanorods. Although a freeze-dried sample showed lower crystallinity and specific surface area, they increased concomitantly with increasing drying temperature. Results suggest that a hydrothermal-like reaction occurs in the samples during drying. With grafting of Cu ions, photocatalytic performance for the decomposition of gaseous 2-propanol (IPA) under visible light was improved. The optimal Cu concentration of the solutions for grafting was around 0.1%. Samples treated using a CuAc2 solution exhibited better photocatalytic activities than those treated using a CuCl2 solution.
    Download PDF (3092K)
  • Yasuhiko BENINO, Yuki OHTSUKI, Shinichi SAKIDA, Tokuro NANBA
    2012 Volume 120 Issue 1407 Pages 490-493
    Published: November 01, 2012
    Released on J-STAGE: November 01, 2012
    JOURNAL FREE ACCESS
    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. 31P 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.
    Download PDF (555K)
  • Makoto KOBAYASHI, Hideki KATO, Masato KAKIHANA
    2012 Volume 120 Issue 1407 Pages 494-499
    Published: November 01, 2012
    Released on J-STAGE: November 01, 2012
    JOURNAL FREE ACCESS
    Morphological control as well as formation of nanoparticles of anatase-type titanium dioxide has been achieved by a solvothermal treatment of a water-soluble citratoperoxotitanium (CPT) complex using ethylenediamine (EDA) as a key solvent in the presence of a given amount of water. When the EDA concentration in the whole solvent (EDA + H2O) remained low less than 12 M, the powder obtained after the solvothermal treatment consisted of spindle-like anatase particles. With an increase of the EDA concentration in the solvent, the shape of the obtained particles changed from spindle to square bipyramid. When another water-soluble oxoglycolatoperoxotitanate complex or TiCl4 was used as a starting source of Ti, similar shaped anatase particles could be obtained by a careful choice of synthetic conditions. Using a mixed solvent of EDA and water, sheet-like titanic acid was produced as an intermediate phase, regardless of the EDA concentration. Therefore, the formation of anatase in the current system may take place through dissolution-recrystallization of titanic acid. The formation of square bipyramidal anatase particle achieved in the present study is not agreement with a reported theoretical calculation of equilibrium phase, because the calculation reveals that truncated square bipyramid-like anatase is obtained under an acidic condition and spindle-like anatase was formed under a basic condition. An adsorption of EDA on particle surface and the pH of the solvent may contribute to the achievement of morphological control.
    Download PDF (1920K)
  • Tomoaki WATANABE, Kazumichi NONAKA, JinWang LI, Kazuhisa KISHIDA, Masa ...
    2012 Volume 120 Issue 1407 Pages 500-502
    Published: November 01, 2012
    Released on J-STAGE: November 01, 2012
    JOURNAL FREE ACCESS
    Because of its use as a mother crystal of red phosphor in white LEDs, SrAlSiN3 is a very interesting complex nitride. Till date, the only examples of europium-doped SrAlSiN3 synthesis have been in high-pressure nitrogen atmospheres at high temperatures above 2000 K at 190 MPa with typical solid-state reaction. In comparison, our research is the first to achieve such synthesis at an extremely low temperature of 773 K at 100 MPa. In addition, we document the first instance of synthesis using supercritical ammonia fluid with NaNH2 as a reaction medium. Moreover, to our knowledge, this report details the first instance of synthesis of europium-doped SrAlSiN3 by using dissolution and precipitation reaction. Reaction temperature and time dependencies of ammonothermal reactions for the product are investigated. The obtained product exhibits a red emission by irradiation of blue light of 460 nm.
    Download PDF (1626K)
  • Yasushi SATO, Valery PETRYKIN, Hiroshi YASUOKA, Masato KAKIHANA
    2012 Volume 120 Issue 1407 Pages 503-508
    Published: November 01, 2012
    Released on J-STAGE: November 01, 2012
    JOURNAL FREE ACCESS
    Polycrystalline samples of YbBa2Cu3O7−d and LuBa2Cu3O7−d were prepared by polymerizable complex method. The combined results of both X-ray diffraction and Raman scattering analyses indicated that YbBa2Cu3O7−d sample was of single phase when the samples were sintered in a low oxygen partial pressure (1%) at relatively low temperature (845°C). On the other hand, LuBa2Cu3O7−d sample was only slightly contaminated with a very small amount of Lu2BaCuO5 and BaCuO2 impurities when the sample was prepared under the same condition as YbBa2Cu3O7−d. Ac complex magnetic susceptibility measurements exhibited that a transition into the superconducting state for YbBa2Cu3O7−d and LuBa2Cu3O7−d samples was sharp and smooth, implying that both of the samples were of “superconducting” single phase. The Tc onset values of the YbBa2Cu3O7−d and LuBa2Cu3O7−d, were 93.4 and 92.3 K, respectively.
    Download PDF (601K)
  • Keita KANENISHI, Shinichi SAKIDA, Yasuhiko BENINO, Tokuro NANBA
    2012 Volume 120 Issue 1407 Pages 509-512
    Published: November 01, 2012
    Released on J-STAGE: November 01, 2012
    JOURNAL FREE ACCESS
    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 33.3Bi2O3–33.3ZnO–33.3B2O3. 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.
    Download PDF (934K)
  • Yongzhao YAO, Takashi SEKIGUCHI, Takeshi OHGAKI, Yutaka ADACHI, Naoki ...
    2012 Volume 120 Issue 1407 Pages 513-519
    Published: November 01, 2012
    Released on J-STAGE: November 01, 2012
    JOURNAL FREE ACCESS
    The influences of sapphire (Al2O3) substrate nitridation on the growth of GaN and InN by plasma-assisted molecular-beam epitaxy (PAMBE) were studied by using reflection high energy electron diffraction (RHEED), atomic force microscopy (AFM), and X-ray diffraction (XRD). Three factors have been investigated, including (1) the effect of ionic nitrogen species; (2) nitridation time; and (3) substrate temperature (Ts). RHEED and AFM results have suggested that although AlN formation on sapphire during nitridation is faster when ionic nitrogen species are present or when Ts is higher, the resultant AlN layer is not as homogeneous as that formed without ionic nitrogen species and/or at lower Ts. An inhomogeneous AlN coverage on sapphire leads to GaN and InN growth with more defects, especially to a serious twist misorientation in the case of InN. Optimal nitridation conditions in this experiment have been found to be applying ion-free nitrogen species at Ts = 300°C for a duration about 300 min.
    Download PDF (3264K)
  • Yuki SHIROSAKI, Hiroki YOSHIHARA, Song CHEN, Mark BLEVINS, Yuri NAKAMU ...
    2012 Volume 120 Issue 1407 Pages 520-524
    Published: November 01, 2012
    Released on J-STAGE: November 01, 2012
    JOURNAL FREE ACCESS
    Silica fiber mats were fabricated by soaking electro-spun poly(vinyl alcohol) fibril mat in NH4OH-catalyzed (Stöber type) colloidal silica sol and silica oligomer solution from HCl-catalysis of the system tetraethoxysilane, ethanol, and water, followed by appropriate heat treatments. The silica fibrils from the Stöber silica sol were hollow nano-tubes (NT) consisting of nano-sized silica particles, while the silica nanofibers (NF) from the acid-catalyzed sol were solid with minimal porosity. A model was proposed for the NF and NT formation processes.
    Download PDF (2431K)
  • Hye Young JUNG, Yoo Youl CHOI, Hyung Keun KIM, Doo Jin CHOI
    2012 Volume 120 Issue 1407 Pages 525-529
    Published: November 01, 2012
    Released on J-STAGE: November 01, 2012
    JOURNAL FREE ACCESS
    An investigation was conducted involving the memory characteristics of the Pt/Al2O3/Y2O3/SiO2/Si structure using a high-k Y2O3 charge trapping layer for SONOS (poly-silicon/oxide/nitride/oxide/silicon)-type nonvolatile memory applications. This work focused on Y2O3 layer deposition at different substrate temperatures, which ranged from 450–550°C by metal organic chemical vapor deposition (MOCVD) and examined the electrical properties and structural differences of each specimen. Results showed that the Y2O3 deposited at 500°C had the highest memory characteristics and reliability than the other deposition condition. The maximum memory window of capacitor with an Y2O3 trapping layer deposited at 500°C was 3.11 V which well endured up to 104 program/erase (P/E) cycles. The results indicated that deposition temperature is one of the most critical factors influencing the charge trapping properties.
    Download PDF (2283K)
  • Satoshi FUKUI, Shinichi SAKIDA, Yasuhiko BENINO, Tokuro NANBA
    2012 Volume 120 Issue 1407 Pages 530-533
    Published: November 01, 2012
    Released on J-STAGE: November 01, 2012
    JOURNAL FREE ACCESS
    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.
    Download PDF (1077K)
  • Takeshi NOMURA, Shunsuke NISHIMOTO, Yoshikazu KAMESHIMA, Michihiro MIY ...
    2012 Volume 120 Issue 1407 Pages 534-538
    Published: November 01, 2012
    Released on J-STAGE: November 01, 2012
    JOURNAL FREE ACCESS
    K2NiF4-type Pr2NiO4 doped with Cu, Cu–Ga, or Co (Pr2Ni0.9Cu0.1O4, Pr2Ni0.75Cu0.25O4, Pr1.91Ni0.71Cu0.24Ga0.05O4, or Pr2Ni0.9Co0.1O4) were synthesized by a solid-state reaction for use as cathodes in an intermediate-temperature (500–700°C) solid oxide fuel cell (IT-SOFC). Pr2NiO4, Pr2Ni0.9Cu0.1O4, Pr2Ni0.75Cu0.25O4, Pr1.91Ni0.71Cu0.24Ga0.05O4, and Pr2Ni0.9Co0.1O4 crystallize in the space group Bmab. Single test cells with samarium oxide doped ceria (SDC) as the electrolyte, Ni-SDC cermet as the anode, and the above-mentioned cathode material were fabricated for cell performance measurements at 700°C. Current interruption measurements and electrochemical impedance spectroscopic analysis revealed that the cathode properties of Pr2NiO4, Pr2Ni0.9Cu0.1O4, Pr2Ni0.75Cu0.25O4, and Pr1.91Ni0.71Cu0.24Ga0.05O4 were comparable to that of La0.6Sr0.4Co0.2Fe0.8O3 (LSCF) and the cathode properties of Pr2NiO4 were improved by doping with Cu or Cu–Ga at the Ni site of Pr2NiO4.
    Download PDF (747K)
  • Dae-Min KIM, Sung-Min LEE, In-Ki KIM, Byung Koog JANG, Dae-Soon LIM, Y ...
    2012 Volume 120 Issue 1407 Pages 539-543
    Published: November 01, 2012
    Released on J-STAGE: November 01, 2012
    JOURNAL FREE ACCESS
    The Y2O3 films were deposited on quartz plates using an electron beam (EB) evaporation method with different interlayer. The two types of interlayer, which were compositionally graded and alternated stacks of Y2O3 and SiO2 layer, were applied with the intent to prevent flaking of the coating due to a thermal mismatch between the Y2O3 film and quartz substrate. The field emission scanning electron microscopy (FESEM) analysis indicated that the Y2O3 film with interlayer which consisting of alternated stacks of Y2O3 and SiO2 layer, shows more structural stability, no crack propagation or flaking of the top layer, than other film samples. The plasma resistance of the Y2O3 films was analyzed by a plasma etching test using inductively coupled plasma (ICP) conditions with a gas mixture of CF4/O2. The etching resistance of the Y2O3 films was evaluated by measurement of etching depth. The etching depths of Y2O3 films with interlayer were shown as 20 times lower than quartz plate.
    Download PDF (2803K)
Feature: Advanced Ceramic Science and Technology in the Western Pacific Rim Area: Technical report
  • Mrinalini MISHRA, Yoshio SAKKA, Agneiska SZUDARSKA, Mikolaj SZAFRAN, T ...
    2012 Volume 120 Issue 1407 Pages 544-547
    Published: November 01, 2012
    Released on J-STAGE: November 01, 2012
    JOURNAL FREE ACCESS
    We present a novel application of gelcasting in a strong magnetic field for texture development in the ternary MAX phase carbide-Ti3SiC2. The applicability of a low-toxic and water soluble monomer-glycerol monoacrylate for gelcasting Ti3SiC2 has been shown. Textured green bodies of Ti3SiC2 with a,b-axis oriented along the direction parallel to the applied magnetic field could be fabricated. The relative green density was found to increase from 34 to 58% with increasing solid-loading (30 to 55 vol %) of the suspension but at the cost of the degree of orientation. The Lotgering’s orientation factor- fL(00l) - on the textured top surfaces varied from 0.81 to 0.2 as the solid-loading increased from 30 to 55 vol %.
    Download PDF (1322K)
Feature: Advanced Ceramic Science and Technology in the Western Pacific Rim Area: Notes
feedback
Top