Advanced Materials

Cover image for Advanced Materials

March 1993

Volume 5, Issue 3

Pages 164–229

  1. Masthead

    1. Top of page
    2. Masthead
    3. Essay
    4. Reviews
    5. Materials Forum
    6. Research News
    7. Book Reviews
    1. Masthead (page 164)

      Version of Record online: 29 OCT 2004 | DOI: 10.1002/adma.19930050301

  2. Essay

    1. Top of page
    2. Masthead
    3. Essay
    4. Reviews
    5. Materials Forum
    6. Research News
    7. Book Reviews
    1. Advanced materials research at NTT (pages 165–166)

      Dr. Masatomo Fujimoto

      Version of Record online: 29 OCT 2004 | DOI: 10.1002/adma.19930050302

      This special issue of Advanced Materials concentrates on the research and development activities of the Japanese telecommunications and electronics company Nippon Telegraph and Telephone (NTT). The work described briefly here, ranging from MBE and MOCVD through computer-aided materials design to optical fibers, liquid crystals and high-Tc superconductors, is presented in more detail in the following articles.

  3. Reviews

    1. Top of page
    2. Masthead
    3. Essay
    4. Reviews
    5. Materials Forum
    6. Research News
    7. Book Reviews
    1. Ferroelectric Liquid Crystals with an alkanoyl group (pages 167–171)

      Shogo Kobayashi, Shigeki Ishibashi, Kazue Takahashi, Shinji Tsuru and Fumio Yamamoto

      Version of Record online: 29 OCT 2004 | DOI: 10.1002/adma.19930050303

      Ferroelectric liquid crystals (FLCs) exhibit properties of interest in applications involving optical communication systems. The materials are characterized by a fast response to an electric field, and materials developed at NTT (e.g. see Figure) have been shown to have the highest spontaneous polarization of any FLC.

    2. Organic materials for nonlinear optics (pages 172–178)

      Dr. Toshikuni Kaino and Satoru Tomaru

      Version of Record online: 29 OCT 2004 | DOI: 10.1002/adma.19930050304

      Polymeric nonlinear optical (NLO) materials show promise for use in NLO devices because of their processability, transparency and large optical nonlinearity. After a brief review of the current status of research on NLO polymers, details are given of recent work at NTT. Copolymers with dyes chemically attached as side chains have been found to show large second-order optical nonlinearity, while third-order NLO amorphous polymers have been obtained by chemically introducing a dye into the backbone of a transparent polymer. Applications as electro-optic phase modulators and waveguides are discussed.

    3. High-Tc superconducting thin films (pages 179–186)

      Dr. Shintaro Miyazawa, Dr. Yasuo Tazoh, Hidefumi Asano, Dr. Yasuhiro Nagai, Dr. Osamu Michikami and Dr. Minoru Suzuki

      Version of Record online: 29 OCT 2004 | DOI: 10.1002/adma.19930050305

      In situ deposition of high-Tc superconducting cuprate thin films has progressed tremendously recently, but further improvements are necessary before these films can be used in devices. This review concentrates on thin film growth technologies for LnBa2Cu3Ox (Ln = Y, Eu)—the Figure shows a boule and wafers of a suitable substrate, NdGaO3—and the fabrication of epitaxial multilayer structures, for example a super-conductor/insulator/superconductor combination.

    4. Fibers for Optical Communications (pages 187–191)

      Dr. Shiro Takahashi

      Version of Record online: 29 OCT 2004 | DOI: 10.1002/adma.19930050306

      Low-loss optical fibers based on silica now have a transmission loss value approaching the theoretical limit, and thus attention has turned to other materials. Fibers for optical communications are reviewed in general, and the methods of loss reduction in silica-based fibers are discussed. Advanced materials and new processing technologies are described for active fibers, in which the light is intentionally modified as it propagates along the fiber, as well as for ultra-low-loss passive fibers.

    5. Compound Semiconductor Ultrathin Films— characterization and control of growth (pages 192–197)

      Dr. Naohisa Inoue

      Version of Record online: 29 OCT 2004 | DOI: 10.1002/adma.19930050307

      The unprecedented control of ultra-thin-film properties required by advanced device concepts has led to the development of novel techniques for both growth and characterization, including cathodoluminescence microscopy, scanning tunneling microscopy and in situ optical diagnostics. In situ electron microscopy can be used to directly observe transient growth processes, revealing unexpected features such as the lateral growth of Ga layers around droplets when the surrounding surface is covered with As (Figure).

    6. Computer-Aided Materials Design for semiconductors (pages 198–206)

      Dr. Tomonori Ito, Dr. Takahisa Ohno, Dr. Kenji Shiraishi and Dr. Eiichi Yamaguchi

      Version of Record online: 29 OCT 2004 | DOI: 10.1002/adma.19930050308

      First-principles calculations enable the interpretation and prediction of various materials properties from a microscopic viewpoint. Such calculations are used in computer-aided materials design, which aims to predict any property of a material from a few elementary input parameters. Current computational methods are briefly reviewed, the prediction of various types of potentially useful behavior of heterovalent species in semiconductors is demonstrated, and developments of new methods, such as a Monte Carlo thin-film growth simulation technique, are discussed.

  4. Materials Forum

    1. Top of page
    2. Masthead
    3. Essay
    4. Reviews
    5. Materials Forum
    6. Research News
    7. Book Reviews
    1. Materials Forum (pages 206–207)

      Version of Record online: 29 OCT 2004 | DOI: 10.1002/adma.19930050309

      This section will return in April.

  5. Research News

    1. Top of page
    2. Masthead
    3. Essay
    4. Reviews
    5. Materials Forum
    6. Research News
    7. Book Reviews
    1. Heteroepitaxy of InP on Si substrates (pages 208–209)

      Dr. Hidefumi Mori, Dr. Mitsuru Sugo and Dr. Yoshio Itoh

      Version of Record online: 29 OCT 2004 | DOI: 10.1002/adma.19930050310

      Applications in optoelectronic integration have generated interest in the heteroepitaxy of III–V compounds on Si. However, the high dislocation density and high tensile stress in heteroepitaxial layers are serious problems in producing optical devices such as laser diodes. This article reports the growth of a high-quality InP layer on Si using a combination of organometallic vapor phase epitaxy and vapor mixing epitaxy. A laser diode has been produced whose stability with time is much better than that of a GaAs/Si laser diode.

    2. Compositional separation in Co[BOND]Cr based alloy films (pages 210–211)

      Dr. Yasushi Maeda

      Version of Record online: 29 OCT 2004 | DOI: 10.1002/adma.19930050311

      Co[BOND]Cr Based alloy thin films are being studied extensively for applications as high-density magnetic recording media. The observation of a compositional microstructure the “chrysanthemum-like pattern” (CP) in the Figure, is the first step towards understanding the mechanisms that make such applications possible. Much work remains to be done on the origin of the compositional separation causing the CP and on methods of controlling the CP.

    3. Atomic layer passivation of GaAs surfaces using InP related compounds (pages 212–214)

      Dr. Kazumi Wada and Dr. Yoshinori Wada

      Version of Record online: 29 OCT 2004 | DOI: 10.1002/adma.19930050312

      Passivation of GaAs surfaces has the important function of reducing the loss of carriers by recombination at surfaces and interfaces. This prevents degradation of the characteristics of minority-carrier injection devices and extends the device lifetime. The new method of surface passivation reported here—the deposition of a few atomic layers of InP related compounds—can replace the far from satisfactory sulfur treatment used so far.

    4. Overwrite repeatability of GeSbTe phase-change-type optical disk media (pages 214–216)

      Dr. Hiroki Yamazaki, Dr. Yasuyuki Sugiyama, Dr. Reiichi Chiba and Dr. Shougo Yagi

      Version of Record online: 29 OCT 2004 | DOI: 10.1002/adma.19930050313

      Phase-change-type erasable optical recording media can be overwritten in a simple process, which should lead to a faster data transfer rate and cheaper optical storage devices. The properties of various protective layer materials for optical disks have been investigated, including their surface flatness (see Figure), reflectivity stability and error modes during repeated overwriting.

    5. High efficiency persistent spectral hole-burning materials (pages 216–219)

      Dr. Hiroyuki Suzuki

      Version of Record online: 29 OCT 2004 | DOI: 10.1002/adma.19930050314

      Persistent spectral hole-burning (PSHB) materials based on donor–acceptor electron transfer have promising characteristics for future memory applications, i.e. high recording speed and high recording density, that cannot be matched by conventional PSHB materials. Novel PSHB materials are described in which spectral holes can be burnt on nanosecond or sub nanosecond time scales. A materials design guideline for optimizing donor-acceptor combinations is presented and goals of future work are discussed.

  6. Book Reviews

    1. Top of page
    2. Masthead
    3. Essay
    4. Reviews
    5. Materials Forum
    6. Research News
    7. Book Reviews

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