Advanced Materials

Cover image for Advanced Materials

December 1992

Volume 4, Issue 12

Pages fmi–fmi, 782–828

  1. Masthead

    1. Top of page
    2. Masthead
    3. Essay
    4. Articles
    5. Communications
    6. Research News
    7. Correction
    8. Book Reviews
    1. Masthead (page fmi)

      Article first published online: 15 SEP 2004 | DOI: 10.1002/adma.19920041201

  2. Essay

    1. Top of page
    2. Masthead
    3. Essay
    4. Articles
    5. Communications
    6. Research News
    7. Correction
    8. Book Reviews
    1. Materials research for advanced solid-state electronic devices (pages 782–785)

      George Gibbons

      Article first published online: 15 SEP 2004 | DOI: 10.1002/adma.19920041202

      GEC-Marconi Materials Technology (GMMT) is actively engaged in a broad-based program of research in semiconducting materials. George Gibbons, the technical director of the GMMT Caswell laboratory, introduces some of this work, which is then described in more detail in several other articles in this issue by members of the laboratory. Interest is focused on how materials technology drives the progress made in solid-state devices and circuits, with the next big advance being expected in the development of optoelectronic integrated circuits.

  3. Articles

    1. Top of page
    2. Masthead
    3. Essay
    4. Articles
    5. Communications
    6. Research News
    7. Correction
    8. Book Reviews
    1. Advanced materials for GaAs Microwave Devices (pages 786–791)

      Dr. Robin S. Smith and Dr. Ian G. Eddison

      Article first published online: 15 SEP 2004 | DOI: 10.1002/adma.19920041203

      The monolithic microwave integrated circuit (MMIC) is revolutionizing microwave applications by making it possible to replace bulky, expensive hybrid circuits by small, reliable, and potentially very low cost chips such as that shown in the Figure. The ion-implantation and molecular beam epitaxy techniques required for their production are described, along with heterojunction bipolar transistors and high electron mobility transistors.

  4. Communications

    1. Top of page
    2. Masthead
    3. Essay
    4. Articles
    5. Communications
    6. Research News
    7. Correction
    8. Book Reviews
    1. Fast electroclinic switching in a ferroelectric LC-polysiloxane (pages 792–794)

      Holger Poths, Dr. Gunnar Andersson, Prof. Kew Skarp and Prof. Rudolf Zentel

      Article first published online: 15 SEP 2004 | DOI: 10.1002/adma.19920041204

      A ferroelectric liquid-crystal (LC) polymer with extremely rapid electroclinic switching is reported: The LC-polysiloxane can optically follow an electric field of more than 100 kHz. This high switching speed should make it possible to transform spoken language into optical signals for transmission through optical fibers. The polymer exhibits strictly linear behavior in the high-temperature region of the smectic A* phase, in which the high-speed switching occurs, while pronounced nonlinearity is found as the smectic C* phase is approached. For applications in which a nonlinear response is acceptable, the greater contrast in this region is a bonus.

    2. Phase-matched optical second-harmonic generation in Langmuir–Blodgett film waveguides by mode conversion (pages 795–798)

      Dr. Mathias Flörsheimer, Munfred Küpfer, Dr. Christian Bosshard, Dr. Herbert Looser and Prof. Peter Günter

      Article first published online: 15 SEP 2004 | DOI: 10.1002/adma.19920041205

      Phase-matched second-harmonk light generation by guided mode conversion has been observed for the first time in nonlinear optically active Langmuir-Blodgett films. The sketch of the experimental setup (Figure) shows how the infrared fundamental beam is coupled via a grating into SiO2/TiO2-DCNAP waveguides with various thicknesses of DCNAP film. The film with the correct thickness for phase matching guides a second-harmonic mode, which is observed as a blue beam, as illustrated in a photograph in the article.

    3. Well-defined pyrrole oligomers: Electrochemical and UV/vis studies (pages 798–801)

      Dr. Gianni Zotti, Stefano Martina, Prof. Gerhard Wegner and Prof. Arnulf-Dieter Schlüter

      Article first published online: 15 SEP 2004 | DOI: 10.1002/adma.19920041206

      The properties of oligo(pyrrole)s can give vital clues to the intrinsic properties and behavior of poly(pyrrole), which is important in the field of polyconjugated conducting polymers but difficult to obtain defect-free. However, up to now little work has been done on oligo(pyrrole)s, perhaps because of their sensitivity to oxygen, which makes their handling and preparation difficult. The reported electrochemical analysis of well-defined pyrrole oligomers has allowed both the determination of the limiting value for the potential of reversible charging of poly(pyrrole) and the production by electrochemical coupling of a virtually defect-free poly(pyrrole).

    4. Crystals of an antiferromagnetic 1,3-butadiyne compared with a ferromagnetic 1,3,5-hexatriyne carrying a 4-Chloro-3-(N-tent-butyl-N-oxyamino)phenyl Group as a Persistent Free Radical Substituent (pages 801–804)

      Katsuya Inoue and Prof. Hüzu Iwamura

      Article first published online: 15 SEP 2004 | DOI: 10.1002/adma.19920041207

      Persistent organic radicals with a ferromagnetic interaction in the crystalline state are few and far between. One example is crystalline 1,3,5-hexatriyne carrying a [4-chloro-3-(N-tert-butyl-N-oxyamino)-phenyl] substituent at position 1. This has been studied and compared with crystalline 1,3-butadiyne (see Figure) carrying the same substituent, which, in contrast, exhibits antiferromagnetic interactions at cryogenic temperatures.

    5. A general approach to NRmath image-stabilized metal colloids in organic phases (pages 804–806)

      Prof. Helmut Bönnemann, Rainer Brinkmann, Rainer Köppler, Peter Neiteler and Joachim Richter

      Article first published online: 15 SEP 2004 | DOI: 10.1002/adma.19920041208

      The stabilization of metal particles in a recent synthesis of colloidal transition metals was achieved by combining the stabilizing agent (NRmath image) with the reducing agent (NR4BEt3H). The disadvantages inherent to this method (the cost of the reducing agent synthesis and the need for stoichiometric amounts of stabilizing agent) have been overcome in the development reported here: NRmath image-stabilized (isolatable) metals of groups 6‒11 are produced by coupling the stabilizing agent to the metal salt that is to be reduced and reducing with simple inorganic and organic reducing agents. These isolatable colloid powders are precursors to highly active homogeneous and heterogeneous metal colloid catalysts.

  5. Research News

    1. Top of page
    2. Masthead
    3. Essay
    4. Articles
    5. Communications
    6. Research News
    7. Correction
    8. Book Reviews
    1. Plasma sprayed anti-reflection coatings for microwave optical components (pages 807–809)

      Dr. Paul Osbond

      Article first published online: 15 SEP 2004 | DOI: 10.1002/adma.19920041209

      Plasma spraying of anti-reflection (AR) coatings onto high permittivity microwave ceramics is a very attractive novel technique for minimizing reflections from optical components. This technique should be able to supersede conventional solutions to the loss of power by reflections, such as the ‘moth-eye’ AR surface (see Figure). Plasma spraying avoids the machining problems presented by the size and spacing of the protuberances required for ‘moth-eye’ AR surfaces for microwave optical ceramic components.

    2. Optoelectronic device technology for coherent optical communication systems (pages 810–813)

      Dr. Brian Debney, Dr. Chris Park and Dr. Judith Hankey

      Article first published online: 15 SEP 2004 | DOI: 10.1002/adma.19920041210

      Optical heterodyning, the principle incorporated in coherent optical communication systems, is of great interest in present-day fiber-optic research because it offers the ability to construct very sensitive optical receivers and to transmit and demultiplex large numbers of closely spaced optical channels carried on a fiber, thus leading to efficient use of the fiber bandwidth. The requirements on materials for heterodyne receivers and semiconductor lasers—indispensable components of coherent optical communication systems—and recent progress made toward satisfying these requirements are discussed, together with device technologies in this field.

    3. Ion implanted material in highly integrated GaAs ICs (pages 813–815)

      Dr. Frederick A. Myers

      Article first published online: 15 SEP 2004 | DOI: 10.1002/adma.19920041211

      Selective ion implantation and epitaxy are beginning to increase the degree of integration of monolithic microwave ICs (MMICs). Most MMICs produced to date have only a single function per chip, for example the C-band phased array radar T/R module illustrated in the Figure, but selective ion implantation has allowed a complex, multifunction GaAs MMIC to be realized recently.

    4. Ferroelectric thin films (pages 816–818)

      Dr. David A. Tossell and Dr. Anil Patel

      Article first published online: 15 SEP 2004 | DOI: 10.1002/adma.19920041212

      Lead-based ferroelectric thin films have many potential pyroelectric and electro-optic applications. Thin-film-based devices are very likely to replace their bulk wafer counterparts within the next few years, particularly where full integration with silicon technology becomes feasible. The sol-gel route is shown to produce PST films with properties approaching those of the bulk, and dual ion beam sputtering is demonstrated to have the capability of significantly affecting the film density, stoichiometry, morphology and even the crystalline phase during the growth of PLZT thin films.

    5. Novel piezoelectric materials (pages 819–822)

      Robert C. Twiney

      Article first published online: 15 SEP 2004 | DOI: 10.1002/adma.19920041213

      The unique properties of piezopolymers endow them with particular advantages for use in electroacoustic devices such as the self-supporting dome hydrophone shown in the Figure. Thin or especially thick films can be fabricated, and three-dimensional forming of the materials can be accomplished by standard techniques. Further interesting possibilities offered by incorporating a ferroelectric ceramic into a non-electroactive polymer matrix are sketched.

  6. Correction

    1. Top of page
    2. Masthead
    3. Essay
    4. Articles
    5. Communications
    6. Research News
    7. Correction
    8. Book Reviews
    1. You have free access to this content
      Correction (page 825)

      Article first published online: 15 SEP 2004 | DOI: 10.1002/adma.19920041215

  7. Book Reviews

    1. Top of page
    2. Masthead
    3. Essay
    4. Articles
    5. Communications
    6. Research News
    7. Correction
    8. Book Reviews

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