Nanostructured Glasses (Nanoglasses):

The Door to a New Glass-based Technology Age: A Glass Age.

Herbert Gleiter

Karlsruhe Institute of Technology - KIT

D-76021 Karlsruhe, GERMANY

herbert.gleiter@kit.edu

Herbert Gleiter Institute of Nanoscience

Nanjing University of Science and Technology

Nanjing 10094, 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 are totally or partially on non-crystalline. One group of them are nano-glasses. They consist of nanometer-sized glassy regions connected by (nanometer-wide) interfacial regions. These interfacial regions have atomic and electronic structures that do not exist in melt-cooled glasses. In fact, all of the interfaces in one material seem to have the same atomic structure which seems to represent the state of lowest free energy of dense disordered matter. Due to their new atomic/electronic structures, the properties of nano-glass differ from the corresponding properties of melt-cooled glasses with the same chemical composition. For example, their ductility, their biocompatibility, their catalytic and ferromagnetic properties are changed by up to several orders of magnitude. Due to these new properties nanoglasses seem to be attractive materials e.g. for medical applicationsin the form of implantation materials. 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. Hence, nanoglasses open the door to new kinds of materials such as solid solutions consisting of ions embedded in a metallic matrix or vice versa showing electronic structures that do not exist in all of the crystalline materials that are available today as well as in the past.

The properties of nano-glasses may be controlled by varying the sizes and/or chemical compositions of the glassy clusters. This opens the perspective of a wide spectrum of new materials with new properties. In other words the present state of development of nanoglases seems comparable to the situation at the beginning of the Bronze Age or the Iron Age. In these cases, the new properties resulted in new technological development periods. Hence the novel properties of nanoglasses may open the door to a new technology age, a “Glass Age”. However, similar cases (e.g. the technological developments based on the discovery of of Al or of Si) indicate that this new Glass Age requires the discovery of economic production methods for nanoglass-based materials (1), (2)

(1) H. Gleiter Small 12 (2016) 2225 – 2233

(2) Editorial Advanced Materials Letters 11 2020 1 - 8

Prof. Dr. Dr. h.c. mult. Herbert Gleiter