Stookey Lecture of Discovery

Nanostructured glasses (nano-glasses): The door to a new glass-based technology age: A glass age

Professor Herbert Gleiter, Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), Germany and the Herbert Gleiter Institute of Nanoscience Nanjing, PR China

Today’s technologies are based primarily on utilizing crystalline materials (e.g. metals, semiconductors or crystalline ceramics). The way to new technologies may be opened by nanostructured materials that have a totally or partially non-crystalline atomic structure. Historically, the oldest group of them (initiated in 1980) are nano-crystalline materials. Due to a high volume fraction (~ 50% interfaces) these nano-crystalline materials were discovered to open the way to a new class of solids characterized by new atomic as well as new electronic structures and novel properties. Today, more than 200 000 papers have been published that are related to these nano-crystalline of materials.

In 1989 a new kind of non- crystalline materials – called nano-glasses - was proposed  and evidenced to exist. They consist of nanometer-sized glassy regions connected by (nanometer-wide) interfacial regions with atomic and electronic structures that do not exist in melt-cooled glasses. Due to their new atomic/electronic structures, the properties of nano-glass differ from the corresponding properties of melt-cooled glasses. For example, their ductility, their biocompatibility, their catalytic and ferromagnetic properties are changed by up to several orders of magnitude. Moreover, they permit the alloying of components e.g. ionic materials (e.g. SiO) and metallic materials (e.g. PdSi glasses) that are immiscible in the crystalline state. The properties of nano-glasses may be controlled by varying the sizes and/or chemical compositions of the glassy clusters which opens the perspective of a new age of technologies - a ”glass age”. A second group of nanostructured partially non-crystalline materials with tunable properties are nano-porous metals with electrolyte filled pores. By applying an external voltage between the electrolyte and the nano-porous metal their properties e.g. their superconductivity, magnetic moment, electric resistivity may be varied. Single or multi-atom switchable contacts represent a third group of these materials. They open a new and very efficient way to produce single or multi-atom transistors.

 

George W. Morey award

Optical fiber meets the Periodic Table: The past, present, and future of the molten core method

Professor John Ballato, Materials Science and Engineering and J. E. Sirrine Endowed Chair in Optical Fiber, Clemson University, USA

Glass, in the form of optical fibers, enables all means of modern communications and a great many other important industrial and consumer uses. However, the principal processes for fabricating optical fiber glasses have the unintended consequences of restricting the range of compositions that can be made into practical fibers. This lecture will discuss the past, present, and future of the molten core method for fabricating a wide variety of novel glassy and crystalline core optical fibers, exhibiting an equally wide variety of fascinating properties not previously known.

Norbert J. Kreidl Award for Young Scholars

Synthesis, structure and properties of pure TeO2 glass, binary and ternary tellurite glasses

Dr. Nagia Tagiara, Theoretical and Physical Chemistry Institute, National Hellenic Research Foundation, Greece

In the context of the PhD thesis entitled “Synthesis, structure and properties of pure TeO2 glass, binary and ternary tellurite glasses”, we synthesized for the first time pure TeO2 glass in sizable quantities by melting in Pt crucibles and quenching using our newly developed intermittent quenching technique.1 Glass transition temperature (Tg), density (ρ) and elastic properties of pure TeO2 glass were measured and its structure was studied by Raman and infrared (IR) spectroscopy.1,2 In parallel, (TeO2)6 and (TeO2)12 clusters were studied by density functional theory (DFT) and the Raman and IR spectra were calculated and compared with the experimental spectra.3 It was found that (i) Tg, ρ, elastic moduli and structure of pure TeO2 glass are distinctly different from those reported for TeO2 glasses melted in alumina crucibles, (ii) pure TeO2 glass has no Te=O bonds, and (iii) its structure consists of trigonal bipyramidal TeO4 units connected by asymmetric and nearly symmetric Te-O-Te bridges (as in γ-ΤeO2), and involves also edge-shared TeO4 units through double oxygen bridges,Te-O2-Te, as in the β-ΤeO2 polymorph.

Varshneya Glass Science lecture

Chalcogenide optical materials: A ‘coming of age’ story

Professor Kathleen Richardson, Pegasus Professor of Optics and Materials Science and Engineering and Florida Photonics Center of Excellence (FPCE) Professor at CREOL/College of Optics and Photonics, University of Central Florida, USA

Chalcogenide materials have been employed in infrared optical systems for decades, but it only within the past several years that chalcogenide glasses (ChGs) and alloys have found their way into designs of optical systems at a scale that enables their transition to the marketplace for broader use in diverse bulk (free-space) and integrated (planar) photonic applications.  With their versatile design flexibility in both composition and form factor, ChGs, glass ceramics and phase change alloys are being widely adapted for a range of applications where legacy materials like Germanium, no longer can serve as a cost effective and sustainable option.  This lecture describes the attributes of ChGs and their alloys and the market opportunities that are pulling these materials out of the lab onto the commercial stage.

Varshneya Glass Technology lecture

From strong bioactive glasses to tough bio-inspired glass-ceramics: A journey towards damage-resistant materials

Dr. Qiang Fu, Senior Research Associate, Corning Incorporated, USA

The quest for damage-resistant engineering materials for biomedical, structural and technical applications is driving the development of high-performance materials with exceptional mechanical properties. Bioactive glass, invented in 1960s, was initially targeted for soft tissue or non-loaded hard tissue regeneration. Despite its brittleness, recent advances in new glass compositions and processing techniques have demonstrated the potential to produce glass scaffolds with strength comparable to that of cortical bone, opening a new avenue for their applications in loaded large bone defects. On the other hand, glass-ceramics were born tough when discovered in 1950s. New improvements in this material family, inspired from natural biological and geological minerals, have made possible unique microstructures and phase assemblages. The resulting glass-ceramics have demonstrated superior damage-resistance due to their exceptional strength and toughness, enabling their applications beyond traditional consumer products.