Advanced Materials

Cover image for Advanced Materials

July 1991

Volume 3, Issue 7-8

Pages fmi–fmi, 332–406

  1. Masthead

    1. Top of page
    2. Masthead
    3. Articles
    4. Communications
    5. Articles
    6. Research News
    1. Masthead (page fmi)

      Version of Record online: 15 SEP 2004 | DOI: 10.1002/adma.19910030701

  2. Articles

    1. Top of page
    2. Masthead
    3. Articles
    4. Communications
    5. Articles
    6. Research News
    1. Advanced materials in the electronics industry (pages 332–333)

      Prof. Feye Meijer

      Version of Record online: 15 SEP 2004 | DOI: 10.1002/adma.19910030702

      Essay: This year sees the 100th anniversary of Philips, one of the world's leading electronics companies. In this special issue an overview of the materials research which forms the basis of the company's development program is provided by researchers from Eindhoven in Holland, and Aachen in Germany. The Essay, from the Director of Research in Einhoven, sets the scene with an account of the general materials requirements in the electronics industry.

    2. Advanced dielectrics: Bulk ceramics and thin films (pages 334–340)

      Dr. Detlev Hennings, Dr. Mareike Klee and Dr. Rainer Waser

      Version of Record online: 15 SEP 2004 | DOI: 10.1002/adma.19910030703

      Review: Ceramic multilayer capacitors used in surface-mount electronics have decreased in size by a factor of four over the last five years while their capacitance per unit volume has increased by the same factor. The preparation and processing procedures applied to ultrafine dielectric ceramic powders used in the capacitors (see Figure), which have resulted in these improvements in size and performance characteristics are described.

    3. Electrocatalytic Hydride-Forming Compounds for rechargeable batteries (pages 343–350)

      Dr. Peter H. L. Notten and Dr. Robert E. F. Einerhand

      Version of Record online: 15 SEP 2004 | DOI: 10.1002/adma.19910030704

      Reviews: Non-toxic intermetallic hydride-forming compounds are attractive alternatives to cadmium as the negative electrode materials in the new generation of Ni/metal hydride rechargeable batteries. High exchange currents and discharge efficiencies even at low temperatures can be achieved using highly electroactive metal alloys containing two different crystallographic phases, an approach which also obviates the need for the inclusion of precious metals.

    4. Silicon molecular beam epitaxy (pages 351–355)

      Dr. Dirk J. Gravesteijn, Dr. Gerjan F. A. van De Walle and Dr. Aart A. van Gorkum

      Version of Record online: 15 SEP 2004 | DOI: 10.1002/adma.19910030705

      Review: The thickness of semiconductor layers in superlattices is constantly being reduced due to the quest for miniaturization of electronic components. Using silicon molecular beam epitaxy (Si-MBE), thin Si or SiGe alloy layers can be epitaxially grown (see Figure) with close control of the dopant profiles of the materials, enabling the production of improved heterojunction bipolar transistors and field effect transistors.

    5. Nanocrystalline Materials for video recorder heads (pages 356–360)

      Dr. Hendrik Jan De Wit, Cor H. M. Witmer and Frank W. A. Dirne

      Version of Record online: 15 SEP 2004 | DOI: 10.1002/adma.19910030706

      Review: High-definition television (HDTV) recording requires magnetic materials able to record much finer detail than the crystalline ferrites in today's video recorder heads. A new multilayer material has therefore been developed which is composed of crystalline iron layers (10 nm) alternating with even thinner amorphous iron-alloy layers. Produced using ion-beam sputtering. the new nanocrystalline materials allow video recording at much higher information densities.

    6. Designing Luminescent Materials (pages 361–367)

      Dr. Michael Bredol, Dr. Ulrich Kynast and Dr. Cornelis Ronda

      Version of Record online: 15 SEP 2004 | DOI: 10.1002/adma.19910030707

      Review: Non-conventional phosphor host materials such as cryptands (see Figure) or zeolites now offer potential alternatives to the traditional inorganic solid-state materials which find applications in e.g. fluorescent lamps, T.V. sets, or X-ray detectors. Recent efforts to further optimize conventional materials are reviewed and a forward look is taken at the new-generation materials which could further extend the physical limits of luminescence.

    7. High-resolution Electron Microscopy of semiconductors and metals (pages 368–378)

      Corrie W. T. Bulle-Lieuwma, Dr. Wim Coene and Dr. A. Frank de Jong

      Version of Record online: 15 SEP 2004 | DOI: 10.1002/adma.19910030708

      Review: Two-dimensional information on the microstructure of materials at a resolution comparable to interatomic distances is crucial for the study of interfaces, defects, growth mechanisms etc. One of the most important analytical methods for gaining such information is high-resolution electron microscopy (HREM). The interpretation of the results on semiconductors, magnetic alloys and multilayers, can often be facilitated through image processing and simulation.

  3. Communications

    1. Top of page
    2. Masthead
    3. Articles
    4. Communications
    5. Articles
    6. Research News
    1. A semiconductive nickel--phosphine coordination polymer** (pages 381–385)

      Prof. Marye Anne Fox and Dr. Daniel A. Chandler

      Version of Record online: 15 SEP 2004 | DOI: 10.1002/adma.19910030709

      Communication: Organometallic polymers with a transition-metal ion incorporated into a conjugated chain are of potential interest as conductors and semiconductors. The structural criteria which are known to enhance conductivity, such as strong ligand–metal interactions, co-planarity of aromatic ligands, and high molecular weight, are met by the new material shown in the Figure.

    2. Intrinsic redox behavior of inert polymer layers filled with copper phthalocyanine pigment (pages 385–388)

      Prof. Fritz Beck and Rolf Jansen

      Version of Record online: 15 SEP 2004 | DOI: 10.1002/adma.19910030710

      Communication: New, inexpensive, stable electrode materials which function on the principle of heterogeneous redox catalysis have been prepared from a mixture of copper phthalocyanine (CuPc) and polytetrafluoroethylene (PTFE) or acrylate/melamine baking varnish. The electrode materials can be simply ‘painted’ on to a substrate and exhibits a greater stability than vapor-deposited layers. As all the materials are readily available applications as synthesis electrodes and in electrochromic displays can be envisaged.

    3. Immobilization of enzymes on langmuir–blodgett films via a membrane-bound receptor. possible. applications for amperometric biosensors (pages 388–391)

      Dr. Wolfgang Schuhmann, Sven-Peter Heyn and Dr. Hermann E. Gaub

      Version of Record online: 15 SEP 2004 | DOI: 10.1002/adma.19910030711

      Communication: An amperometric biosensor for glucose, based on an immunological recognition process between an antigen binding fragment (Fab, see Figure), immobilized in a planar bilayer lipid membrane, and glucose oxidase. The enzyme-catalyzed formation of H2O2 in the presense of glucose can be detected amperometrically by means of an electrode. The principle of this sensor is also applicable for sensing a wide range of other substrates.

  4. Articles

    1. Top of page
    2. Masthead
    3. Articles
    4. Communications
    5. Articles
    6. Research News
    1. Materials Forum (page 391)

      Version of Record online: 15 SEP 2004 | DOI: 10.1002/adma.19910030712

  5. Research News

    1. Top of page
    2. Masthead
    3. Articles
    4. Communications
    5. Articles
    6. Research News
    1. Anisotropic networks formed by photopolymerization of liquid-crystalline molecules (pages 392–394)

      Dr. Rifat A. M. Hikmet, Johan Lub and Dirk J. Broer

      Version of Record online: 15 SEP 2004 | DOI: 10.1002/adma.19910030713

      Research News: Oriented polymeric structures can possess anisotropic optical, electrical, and thermo-mechanical properties which make them of interest for application in the production of polarizers, waveguides, optical filters, and wave plates. One method of producing such structures, the photopolymerization of self organizing liquid-crystalline molecules is discussed and the applications of structures derived from nematics, cholesterics, and anisotropic gels described.

    2. Submicron-powder starting materials for advanced ferrites (pages 394–396)

      Dr. Arjan Noordermeer and Dr. Marijke M. E. Severin-Vantilt

      Version of Record online: 15 SEP 2004 | DOI: 10.1002/adma.19910030714

      Research News: The dependence of the microstructure on the processing route and conditions has a profound effect on the performance of ferrites (magnetic oxides) in applications such as cores for transformers and inductors, and in video heads. Methods of optimizing the microstructures of the materials for particular applications are discussed with special emphasis on a consolidation method which is a combination of sedimentation and filtration.

    3. Co/Pt multilayers for magneto-optical recording (pages 397–399)

      Dr. W. Bas Zeper, Dr. Hans W. van Kesteren and Dr. Peter F. Carcia

      Version of Record online: 15 SEP 2004 | DOI: 10.1002/adma.19910030715

      Research News: Magnetic multilayers have emerged as an alternative to amorphous rare-earth transition-metal alloys for application in magneto-optical recording media. Their success has been due to their intrinsic resistance to oxidation and corrosion, large Kerr rotation at shorter wavelengths, ease of preparation, and thermal stability. The Figure shows thermo-magnetically written domains on a Co/Pt disc, written at the given fields.

    4. Potassium lithium niobate: A frequency doubler for (Al,Ga)As lasers (pages 399–401)

      Dr. Martin Ouwerkerk

      Version of Record online: 15 SEP 2004 | DOI: 10.1002/adma.19910030716

      Research News: Doubling the frequency of light from an (Al,Ga)As laser quadruples its spot density and also, therefore, the amount of information which can be stored on an optical disc. By varying the lithium content of the title compound a frequency doubling material has been developed which can be tuned from 720 to over 920 nm producing a highly efficient blue laser capable of high-density optical recording.

    5. Organic materials for frequency doubling (pages 401–403)

      Dr. E. G. J. Staring, Dr. G. L. J. A. Rikken, Dr. C. J. E. Seppen, Dr. S. Nijhuis and Dr. A. H. J. Venhuizen

      Version of Record online: 15 SEP 2004 | DOI: 10.1002/adma.19910030717

      Research News: Organic nonlinear optical (NLO) materials offer and alternative approach to a blue laser to the inorganic materials described by Ouwerkerk (this issue). The criteria for efficient organic NLO materials which are transparent at both 820 nm, the emmission frequency of GaAs/AlGaAs diode lasers, and 410 nm, the frequency of the frequency-doubled blue light are discussed with special reference to compounds studied at Philips (e.g. see Figure).

    6. Upconversion in fluoride glass fibers (pages 403–406)

      Dr. Manuel Oomen

      Version of Record online: 15 SEP 2004 | DOI: 10.1002/adma.19910030718

      Research News: Compact visible (blue) lasers are required for applications such as barcode reading, laser printing, and high-definition optical recording. An alternative method to frequency doubling to obtain blue laser light is the up-conversion of infrared light. In this process photons are converted to higher energies by generating high-energy excited states in the energy level scheme of a rare-earth ion which then emit at a higher frequency than that of the infrared excitation source.