At the beginning of July, the two researchers Professor Himanshu Jain and Professor Walter Kob were honored with the Otto SCHOTT Research Award valued at 25,000 euros during the »International Congress of Glass 2007« in Strasbourg. This award is bestowed every other year on an alternating basis with the Carl Zeiss Research Award to recognize exceptional scientific achievements in fundamental research and technology development in the areas of specialized materials, components and systems for applications in optics, electronics, solar energy, health and lifestyle. Both research awards are governed by the Donors’ Association for the Promotion of Sciences and Humanities in Germany.
”Jellyfish model” explains the movement of atoms inside glass
Professor Himanshu Jain (Lehigh University, Bethlehem/PA, U.S.A.) has been heading the National Science Foundation’s »International Materials Institute for New Functionality in Glass (IMI-NFG)« since 2004. He received the award for his outstanding contributions towards promoting the basic understanding of the dynamics of atoms in glass. He was previously recognized by the international »Zachariasen Award« for exceptional contributions towards glass research.
Studies established the basic characteristics of this atomic movement; however its physical description remained a mystery until a clue dawned on Professor Jain during a boat ride he took to the Isle of Skye, of Scotland’s west coast. Watching the hundreds of jellyfish in the Sea of the Hebrides, he noted that they were not swimming, but rather wiggling without moving very far. The following description of the dynamics of atoms at low temperatures emerged as a result: The ”jellyfish” movements are from a group of atoms which collectively move between different configurations, much like the wiggling of a jellyfish in the ocean. These fluctuations are much slower than typical atom vibrations and depend on the material’s local and medium range structure. The ”jellyfish” movements also occur at room temperature, but become significant only at much higher frequencies. Thus the dynamic properties of glass such as dielectric loss at microwave frequencies are directly predicted from the low frequency studies at low temperatures.
Simulations show dynamics of supercooled fluids
Born in Switzerland, Professor Walter Kob is
The research fields of Professor Kob include the dynamics of supercooled liquids and the nature of glass transformation, the structure and dynamics of gels, sodium silicate melts and glasses and aging of systems made of glass. His research focuses mainly on investigating the static and dynamic properties of disordered systems, such as simple liquids, textured glasses, Potts glasses or polymers, with aid from computer simulations and other statistical mechanics methods. These computer simulations were developed in the last decade in order to obtain insight into the microscopic properties of materials.
In the »classical force fields« approach, one postulates the interactions between the atoms and then uses these postulated forces to solve Newton’s equations of motion. The precise form of these forces is determined from experimental data or from ab initio simulations. For this reason, this approach is not independent from experiments or more sophisticated simulations, but is approximately 10,000 times faster. Much larger systems can be simulated in the same time, as a result. Computer simulations are not yet a ”perfect” tool, because the properties of glasses depend on the cooling rate with which the glass has been produced and in simulations theses rates are many orders of magnitude higher than the rates used in real life. Nevertheless, in the near future, simulations will be part of the standard tools of research in any material science laboratory.
Schott: Outstanding Models
The dynamics of atoms inside glass and computer simulations that make it possible to project the physical properties of materials are the main focuses of the researchers who were recognized with the Otto SCHOTT Research Award 2007.