15 Fakultätsübergreifend / Sonstige Einrichtung
Permanent URI for this collectionhttps://elib.uni-stuttgart.de/handle/11682/16
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Item Open Access Ein 1λ5, 3λ5, 5λ3-Triphosphabenzol-Derivat(1986) Fluck, Ekkehard; Becker, Gerd; Neumüller, Bernhard; Knebl, Robert; Heckmann, Gernot; Riffel, HeinzDie erste Ringverbindung mit (PC)3-Gerüst, die Titelverbindung 3, wurde wie unten skizziert hergestellt. Die 13C-NMR-Daten deuten auf einen hohen Ylid-Charakter der Gruppierung C4-P5-C6 hin.Item Open Access A 1λ5,3λ5,5λ3-triphosphabenzene derivative(1986) Fluck, Ekkehard; Becker, Gerd; Neumüller, Bernhard; Knebl, Robert; Heckmann, Gernot; Riffel, HeinzThe first ring compound containing the (P=C)3 skeleton, the title compound 3, was prepared as shown below. 13C-NMR data indicate a highly ylidic character of the C4-P5-C6 grouping.Item Open Access 1,3,5-Tris(dimethylamino)benzol mit Iod und 1,3,5-Tricyanobenzol : eine ungewöhnliche Dimerisierung und ein "normaler" Donor/Akzeptor-Komplex(1988) Keller, Heimo J.; Niebl, Roland; Renner, Gerd; Ruhr, Dorothea von der; Schweitzer, DieterWir sind auf der Suche nach "organischen" Ferromagneten. Als Zielsubstanz haben wir kristallisierte Radikal-Ionen mit bahnentarteten Grundzuständen ausgewählt. Molekulare Festkörper aus planaren organischen Radikalionen zeigen ein breites Spektrum teilweise recht interessanter physikalischer Eigenschaften, die durch kollektives Elektronenverhalten zu erklären sind. In den letzten Jahren wurde vor allem das elektrische Verhalten dieser Substanzen untersucht. Dies führte zur Entdeckung einer Vielzahl "organischer Metalle", von denen einige bei tiefer Temperatur auch supraleitend werden.Item Open Access 1,8-dipyrenylnaphthalenes : syntheses, molecular structure, and spectroscopic properties(1984) Wahl, Peter; Krieger, Claus; Schweitzer, Dieter; Staab, Heinz A.Syntheses of the 1,8-dipyrenylnaphthalenes 1-3 are reported. The stereoisomers 1 and 2 were separated; their structural assignment is based on 1H NMR, on the optical activity of 2, and on X-ray structure analyses of 1 and 2. Kinetic parameters for the isomerisation 2 = 1 were determined by optical rotation measurements. - Emission spectra of 1 - 3 are discussed in comparison to monopyrenyl compounds 4 and 8. For 1 and 3 typical 'excimer-like' fluorescence is observed. The difference between 1 and 2 clearly demonstrates the dependence of excimer interactions between the pyrene units on the mutual orientation of the π-systems involved. - On the basis of X-ray analyses the molecular structures of 1- 3 are discussed with emphasis on π···π-interactions between the pyrene units.Item Open Access 10 Gb/s monolithic integrated MSM-photodiode AlGaAs/GaAs-HEMT optoelectronic receiver(1991) Hurm, Volker; Rosenzweig, Josef; Ludwig, Manfred; Benz, Willi; Osorio, Ricardo; Berroth, Manfred; Hülsmann, Axel; Kaufel, Gudrun; Köhler, Klaus; Raynor, Brian; Schneider, JoachimA photoreceiver based on a metal-semiconductor-metal (MSM) photodiode and AlGaAs/GaAs HEMTs is presented. The photoreceiver was fabricated using a 0.5-μm recessed-gate process for double delta-doped quantum-well HEMTs. The following mean values for the enhancement and depletion HEMT parameters, respectively, have been obtained: threshold voltages of 0.1 and -0.5 V, transconductances of 500 and 390 mS/mm, source resistances of 0.7 and 0.6 Ω-mm, and transit frequencies of 35 and 30 GHz. This process includes photodiodes. A deep wet etch was used to deposit the photodiodes on an undoped GaAs buffer layer.Item Open Access 10 Gbit/s monolithic integrated optoelectronic receiver using an MSM photodiode and AlGaAs/GaAs HEMTs(1991) Hurm, Volker; Rosenzweig, Josef; Ludwig, Manfred; Axmann, Albert; Benz, Willi; Berroth, Manfred; Osorio, Ricardo; Hülsmann, Axel; Kaufel, Gudrun; Köhler, Klaus; Raynor, Brian; Schneider, JoachimA 10 Gbit/s monolithic integrated optoelectronic receiver has been fabricated with a metal-semiconductor-metal (MSM) photodiode and enhancement/depletion 0.5 μm recessed-gate AlGaAs/GaAs HEMTs. A -3 dB bandwidth of 11.3 GHz has been achieved.Item Open Access 11.6 Gbps 1:4 demultiplexer using double pulse doped quantum well GaAs/AlGaAs transistors(1991) Lang, Manfred; Nowotny, Ulrich; Berroth, ManfredAn ultrahigh speed 4 bit demultiplexer circuit has been developed and fabricated using a recessed gate process for enhancement and depletion transistors with 0.3 mu m gate length. First results show a data rate of 11.6 Gbit/s and a power consumption of 165 mW at 0.85 V supply voltage, including four 50 Omega buffers.Item Open Access 13C nuclear magnetic relaxation studies at 62 MHz(1971) Jaeckle, H.; Haeberlen, Ulrich; Schweitzer, DieterAn apparatus suitable to measure 13C relaxation times T1 and T2 in liquids at 62 MHz is described. The required field of 58 kG is generated by a superconducting magnet. Results of T1 measurements on a variety of liquids, including benzene, derivatives of benzene, saturated rings, CS2, and others are reported. They are discussed in terms of dipole-dipole interactions, spin-rotation interactions and anisotropic chemical shifts, the latter of which turn out to play only a minor role. Intramolecular dipole-dipole interactions are found to provide by far the most important spin-lattice relaxation mechanism, whenever protons are bound directly to the carbons under investigation, even when the samples contain dissolved oxygen.Item Open Access 14 GHz bandwidth MSM photodiode AlGaAs/GaAs HEMT monolithic integrated optoelectronic receiver(1993) Hurm, Volker; Ludwig, Manfred; Rosenzweig, Josef; Benz, Willi; Berroth, Manfred; Bosch, Roland; Bronner, Wolfgang; Hülsmann, Axel; Köhler, Klaus; Raynor, Brian; Schneider, JoachimA monolithic optoelectronic receiver consisting of an MSM photodiode and a two-stage amplifer has been fabricated using an enhancement/depletion 0.3 μm recessed-gate AlGaAs/GaAs HEMT process. The band-width of 14.3 GHz implies suitability for transmission rates of up 20 Gbit/s. The transimpendance is 670 Ω (into 50 Ω) and the projected sensitivity is 16.4 dBm (BER = 10 -9).Item Open Access 15 Gbit/s integrated laser diode driver using 0.3 μm gate length quantum well transistors(1992) Wang, Zhigong; Berroth, Manfred; Nowotny, Ulrich; Gotzeina, Werner; Hofmann, Peter; Hülsmann, Axel; Kaufel, Gudrun; Köhler, Klaus; Raynor, Brian; Schneider, JoachimAn integrated laser diode driver was realised using enhancement/depletion 0.3 μm recessed-gate AlGaAs/GaAs quantum well transistors. Fully-open eye diagrams were observed at bit rates up to 10 Gbit/s with 50 Ω loads. The maximum DC and modulation current were 25 and 45 mA, respectively. The power consumption is less than 450 mW.Item Open Access 16 x 16 bit parallel multiplier based on 6 K gate array with 0.3 μm AlGaAs/GaAs quantum well transistors(1992) Thiede, Andreas; Berroth, Manfred; Hurm, Volker; Nowotny, Ulrich; Seibel, Jörg; Gotzeina, W.; Sedler, Martin; Raynor, Brian; Köhler, Klaus; Hofmann, Peter; Hülsmann, Axel; Kaufel, Gudrun; Schneider, JoachimThe design and performance of a 16x16 bit parallel multiplier based on a 6 K gate array will be presented. This LSI semicustom IC demonstrates the high potential of the authors' AlGaAs/GaAs quantum well FETs with a gate length of 0.3 μm. The best multiplication time measured was 7.2 ns.Item Open Access 18 Gbit/s monolithically integrated 2:1 multiplexer and laser driving using 0.3 μm gate length quantum well HEMTs(1992) Wang, Zhigong; Nowotny, Ulrich; Berroth, Manfred; Bronner, Wolfgang; Hofmann, Peter; Hülsmann, Axel; Köhler, Klaus; Raynor, Brian; Schneider, JoachimA monolithically integrated 2:1 multiplexer and laser diode driver was developed, using AlGaAs quantum well HEMTs of 0.3 μm gate length. The DC and modulation current is 25 and 45 mA, respectively. Open eye diagrams were measured at bit rates up to 18 Gbit/s with pseudorandom data streams.Item Open Access An 18-34-GHz dynamic frequency divider based on 0.2-μm AlGaAs/GaAs/AlGaAs quantum-well transistors(1993) Thiede, Andreas; Berroth, Manfred; Nowotny, Ulrich; Seibel, Jörg; Bosch, Roland; Köhler, Klaus; Raynor, Brian; Schneider, JoachimThe design and performance of a dynamic frequency divider was presented. This digital IC demonstrates the ability of the authors' AlGaAs/GaAs/AlGaAs quantum-well FETs with gate lengths of 0.2 μm. Stable operation was achieved in the frequency range from 18 GHz up to 34 GHz with a power consumption of 250 mW. To the authors' knowledge, this is the best result ever reported for HEMT circuits, and is similar to the frequency limit achieved by use of AlGaAs/GaAs HBTs.Item Open Access (2,2,8,8-tetramethyl-5-oxa-4,6-diphospha-3,6-nonadiene)tetrakis[dicarbonyl(methylcyclopentadienyl)manganese], the first complexed bis(phosphavinyl) ether(1987) Ziegler, Manfred L.; Balles, Rainer; Nuber, Bernd; Becker, Gerd; Schmidt, Helmut; Kanellakopulos, Basil; Powietzka, BernhardThe title compound 1 is the complex of a novel ligand. It is formed from [(CH3C5H4)Mn(CO)2·thf] and (CH3)3C-C=P, presumably with uptake of H2O. The bis(phosphavinyl) ether in 1 functions as an 8-electron donor toward the four (CH3C5H4)Mn(CO)2 units (abbreviated here as Mn).Item Open Access 2,2-Dimethylpropylidinphosphan, eine stabile Verbindung mit einem Phosphoratom der Koordinationszahl 1 (Acyl- und Alkylidenphosphane ; 15)(1981) Becker, Gerd; Gresser, Gudrun; Uhl, WernerIn the presence of small amounts of solid sodium hydroxide, (2,2-dimethyl-1-(trimethyl-siloxy)propylidene]-trimethylsilylphosphine reacts at + 20° C to give hexamethydisiloxane and 2,2-dimethylpropylidynephosphine (2). In contrast to similar alkylidynephosphines this compound is stabIe at room temperature. The IR and mass spectrum are discussed, and 1 H, 13 C and 31 PNMR spectral data are given.Item Open Access [2.2]- and [3.3]tetrathiafulvalenophanes(1980) Ippen, Joachim; Chu, Tao-pen; Starker, Barbara; Schweitzer, Dieter; Staab, Heinz A.In the "metallic" conducting 1:1 complex of tetrathiafulvalene (TTF) and tetracyanoquinodimethane (TCNQ), donor and acceptor molecules form separate stacks in the crystal. In order to enforce other TTF/TCNQ arrangements by altering the molecular architecture the phane-like bridged TTF-paracyclophanes (1), n = 3, and (2) were first synthesized. To do this a novel reaction sequence had to be developed which also facilitated synthesis of the tetrathiafulvalenophanes (3)/(4) (and the corresponding [2.2]-derivatives). (3)/(4) and TCNQ form a 1:4 complex having a conductivity of σ = 5 × 10−3 to 10−2 [Ω cm]−1 (single crystal, long axis, 300 K).Item Open Access [2.2]- und [3.3]Tetrathiafulvalenophane(1980) Ippen, Joachim; Chu, Tao-pen; Starker, Barbara; Schweitzer, Dieter; Staab, Heinz A.Um bei Charge-Transfer-Systemen, die als elektrische Halbleiter oder Leiter interessant sein könnten, durch Änderung der Molekularchitektur das Kristallgitter systematisch zu variieren, synthetisierten wir [2.2]- und [3.3]Tetrathiafulvalenophane ("TTF-Phane").Item Open Access A 2.5 ns 8 x 8-b parallel multiplier using 0.5 μm GaAs/GaAlAs heterostructure field effect transistors(1991) Berroth, Manfred; Hurm, Volker; Nowotny, Ulrich; Hülsmann, Axel; Kaufel, Gudrun; Köhler, Klaus; Raynor, Brian; Schneider, JoachimTo increase performance of GaAs LSI digital circuits, a 0.5 μm recessed gate process has been developed and utilized for an 8x8-b parallel multiplier. The chip contains about 3000 heterostructure field effect transistors and has a power consumption of 1.5 W. The best results of the maximum multiplication time measured were below 2.5 nsec.Item Open Access 20 Gbit/s 2:1 multiplexer using 0.3 μm gate length double pulse doped quantum well GaAs/AlGaAs transistors(1991) Nowotny, Ulrich; Lang, Manfred; Berroth, Manfred; Hurm, Volker; Hülsmann, Axel; Kaufel, Gudrun; Köhler, Klaus; Raynor, Brian; Schneider, JoachimA high speed 2:1 multiplexer circuit in source coupled FET logic has been developed and fabricated using a recessed gate process for enhancement and depletion transistors with 0.3μm gate length. First results show a data rate of over 20 Gbit/s at 5 V supply voltage and 250 mW power consumption. The output voltage swing is adjustable between 0.3 V and 0.8 V for a 50 Ohm load. The out-put level can be varied between +1 V an -1 V. Comparison between simulation and measurement shows very good agreement.Item Open Access 28-51 GHz dynamic frequency divider based on 0.15 μm T-gate Al0.2Ga0.8As/In0.25Ga0.75As MODFETs(1993) Thiede, Andreas; Tasker, Paul; Hülsmann, Axel; Köhler, Klaus; Bronner, Wolfgang; Schlechtweg, Michael; Berroth, Manfred; Braunstein, Jürgen; Nowotny, UlrichThe design and performance of a 28-51 GHz dynamic frequency divider based on pseudomorphic Al0.2Ga0.8As/In0.25Ga0.75As MODFETs with 0.15 μm mushroom-shaped gates are presented. The circuit has a power consumption of approximately 440 mW and a chip area of approximately 200x220 μm2.