Crystallology

  • Affordable detectors for gamma radiation

    single crystals made of lead halide perovskites Empa

    A research team at Empa and ETH Zurich has developed single crystals made of lead halide perovskites, which are able to gage radioactive radiation with high precision. Initial experiments have shown that these crystals, which can be manufactured from aqueous solutions or low-priced solvents, work just as well as conventional cadmium telluride semi-conductors, which are considerably more complicated to produce. The discovery could slash the price of many radio-detectors – such as in scanners in the security sector, portable dosimeters in power stations and measuring devices in medical diagnostics.

  • Das MPQ päsentiert den Original-Laser

    Prof. Theodore Maiman (Foto: K. Maiman)

    Im Jahr 1960 begann eine neue Ära der Technologiegeschichte. Theodore Maiman stellte den ers-ten funktionierenden Laser der Öffentlichkeit vor. Ein kleines Gerät bestehend aus einer Blitzlampe, einem Rubinkristall und einer Hülse aus Metall. Maimans erster Laser hat die Jahrzehnte überdauert. Jetzt ist das Original im Foyer des Max-Planck Instituts für Quantenoptik (MPQ) in Garching b. München in einer kleinen Ausstellung zu sehen. Zusammen mit dem Laser präsentiert das MPQ das Original-Laborbuch von Theodore Maiman mit seinen bahnbrechenden Skizzen des Geräts. Die Ausstellung ist ab dem 12. Dezember 2016 kostenlos zu besichtigen am Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Str.1, 85748 Garching; täglich von 9 bis 17 Uhr. Journalisten sind herzlich zur Ausstellungseröffnung am 12. Dezember 2016 um 15 Uhr im Foyer des MPQ eingeladen.

  • Electron highway inside crystal

    Step edges on topological crystalline insulators may lead to electrically conducting pathways where electrons with opposite spin spin move in converse directions - any U-turn is prohibited. Picture: Thomas Bathon/Paolo Sessi/Matthias Bode

    Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their work in the journal Science. Topological insulators are currently the hot topic in physics according to the newspaper Neue Zürcher Zeitung. Only a few weeks ago, their importance was highlighted again as the Royal Swedish Academy of Sciences in Stockholm awarded this year's Nobel Prize in Physics to three British scientists for their research of so-called topological phase transitions and topological phases of matter.

  • Kristalluntersuchung mit dreidimensionalen Beugungsmustern

    Kristalluntersuchung mit dreidimensionalen Beugungsmustern | Dreidimensionale Röntgenbeugungsmethode zur Bestimmung der kristallographischen Textur Abbildung: Wiley-VCH

    Trifft Röntgenstrahlung auf einen Kristall wird sie gebeugt und abgelenkt. Die sich daraus ergebenden Beugungsmuster werden auf einer Detektorfläche registriert und sind zweidimensionale Projektionen der Kristallstruktur. Diese Methode wird schon lange zur Strukturaufklärung genutzt. Forschern ist es nun gelungen dieser Projektion eine dritte Dimension hinzuzufügen: die Röntgenphotonenernergie.

  • Kristallzüchtung für komplexe Messaufgaben in der 5G-Technologie

    Kristallzüchtung für komplexe Messaufgaben in der 5G Technologie | Ferrit-Einkristalle für Hochfrequenz-Filterkomponenten gezüchtet aus Hochtemperaturlösungen Photo: INNOVENT e.V.

    Wissenschaftler der Industrieforschungseinrichtung INNOVENT züchten einkristalline Ferritmaterialien für die Mikrowellenmesstechnik. Erstmals werden damit durchgehende Empfangsbereiche von Signal- und Spektrumanalysatoren bis 85 GHz für anspruchsvolle Messaufgaben auf den Gebieten Automotive Radar, 5G und andere drahtlose Kommunikation realisiert.

  • Meteoriteneinschlag im Nano-Format

    Mit energiereichen Ionen lassen sich erstaunliche Nanostrukturen auf Kristalloberflächen erzeugen. Experimente und Berechnungen der TU Wien können diese Effekte nun erklären.

  • Porous crystalline materials: TU Graz researcher shows method for controlled growth

    Porous cystalls called MOFs on a comparatively large surface area of one square centimetre. © Nature Materials 2016 Falcaro et.al.

    Microporous crystals (MOFs) have a great potential as functional materials of the future. Paolo Falcaro of TU Graz et al demonstrate in Nature Materials how the growth of MOFs can be precisely controlled on a large scale. Porous crystals called metal-organic frameworks (MOFs) consist of metallic intersections with organic molecules as connecting elements. Thanks to their high porosity, MOFs have an extremely large surface area. A teaspoonful of MOFs has the same surface area as a football pitch. These countless pores situated in an extremely small space offer room for “guests” and can, for example, be used for gas storage or as “molecular gate” for separation of chemicals.

  • Single crystal growth in hot air: nice and easy

    Schematic of the growth setup. The desired single crystals grow from separated educts at 1020°C via vapor transport. The condensation takes place at spikes placed in between the starting materials. © University of Augsburg/EP VI

    Physicists from Augsburg University together with colleagues from Oxford report on a novel method for the growth of lithium-based transition metal oxides. Augsburg/PhG/KPP -The synthesis of ceramic crystals often requires very complicated methods. Starting materials in form of powders have to be mixed, pressed and pre-reacted in order to allow for single crystal growth from the melt at elevated temperatures. Or samples are grown from solution or chemical vapor transport in complex processes. However, so far none of the established methods yields single crystals of lithium iridate - despite the great interest in this material that was initiated by the prediction of highly unusual magnetic properties.

  • Tailor-Made Membranes for the Environment

    Transmission electron microscope image of the membrane, provided by the Ernst Ruska-Centre. The two phases for proton and electron conduction are marked in colour. Forschungszentrum Jülich

    Jülich, 30 November 2016 – The combustion of fossil energy carriers in coal and gas power plants produces waste gases that are harmful to the environment. Jülich researchers are working on methods to not only reduce such gases, but also utilize them. They are developing ceramic membranes with which pure hydrogen can be separated from carbon dioxide and water vapour. The hydrogen can then be used as a clean energy carrier, for example in fuel cells. The researchers have now been able to increase the efficiency of these membranes to an unprecedented level. Their research results were published in Scientific Reports.