SCHOTT solutions no. 1/2012 > Research and Technology

Testing of a mirror segment made of ZERODUR® glass-ceramic. This is the ­mirror substrate material of choice for use in large telescopes. Photo: SCHOTT/A. Sell

A Material with 
Future Potential


Renowned experts held a scientific colloquium to discuss new insights and developments in the area of glass-ceramics and related materials.


Christine Fuhr

By developing the glass-ceramic ZERODUR®, Professor Jürgen Petzoldt, a former member of the SCHOTT Board of Management, ranks among the outstanding personalities in the company’s history. At the same time, his work has had an enduring effect on the scientific glass community. To mark the first anniversary of Jürgen Petzoldt’s passing, SCHOTT organized a memorial colloquium together with the German Society of Glass Technology that was attended by more than 100 guests, including leading researchers from Japan, the United States, Brazil and Germany. They gave presentations on the past and current status of research and technology development but also the future potential that glass-ceramic holds as an incredibly versatile material. As Prof. Edgar Zanotto from the University Sao Carlos (Brazil) noted, a researcher by the name of Stanley D. Stookey discovered the glass-ceramic more or less by accident from a lithium disilicate glass with precipitated silver particles when he overheated a melting furnace in 1953. The first commercial glass-ceramics were introduced to the market in the aviation industry and the consumer sector in the form of household china towards the end of the 50s. Nevertheless, this material was not adopted for use in science and industry until after Petzoldt had completed his fundamental work on nucleation and crystallization that allowed for ZERODUR® to be successfully positioned as the standard material for astronomic mirror substrates and the “revolution in the kitchen” that followed with CERAN® glass-ceramic cooktop panels. Professors Joachim Deubener (TU Clausthal) and Christian Rüssel (Otto Schott Institute, Jena) explored the progress that has been made in the area of nucleation since then and the latest findings on crystal growth. The laser fine structuring processes introduced by Prof. Takayuki Komatsu (Nagaoka University of Technology, Japan) provided yet another striking example of the versatility of glass-ceramics.
Put together the presentations and speeches for the colloquium (Top, left to right): Prof. Helmut Schaeffer (former Managing Director of the DGG/Hüttentechnische Vereinigung), Fabio Nicoletti (President of the ICC), Research Fellow Dr. Roland Langfeld, Dr. Ulrich Fotheringham (both SCHOTT); Center, left to right: Prof. Hideo Hosono (Tokyo Institute of Technology), Prof. Wolfgang Pannhorst (SCHOTT), Dr. Hans-Joachim Konz (member of the SCHOTT Management Board, responsible for Research & Technology), Prof. Dietrich Lemke (MPI for Astronomy), Prof. Edgar Zanotto (University Sao Carlos, Brazil), Prof. Joachim Deubener (TU Clausthal); Below, left to right: Prof. Christian Rüssel (Otto Schott Institute for Glass Chemistry, Jena), Prof. Udo Ungeheuer, Chairman of the Board of Management of SCHOTT AG, Dr. Ina Mitra, Dr. Yvonne Menke (both SCHOTT), Prof. Takayuki Komatsu, Nagaoka University of Technology, and Dr. Mark Davies (SCHOTT). Photo: SCHOTT/A. Sell
SCHOTT revolutionized the kitchen in 1973 with its CERAN® glass-­ceramic cooktop panels. Prof. Jürgen Petzold is considered to be one of the fathers of this product. Photos: (top) SCHOTT/J. Meyer, (below) SCHOTT/H. Fischer
Today, SCHOTT is capable of custom manufacturing glass-ceramic products to meet specific customer requirements by using simulation techniques, Senior Scientist Dr. Ina Mitra explained. This applies to both aesthetic aspects like the color of a glass-ceramic to be used as a cooktop panel as well as technical challenges like manufacturing lightweight mirrors that can ­occasionally be quite large. Furthermore, SCHOTT is currently focusing on new applications, electrolytes for batteries, for ­instance, in the area of research.

In his exciting presentation through space, Prof. Lemke (Max Planck Institute for Astronomy, Heidelberg) explained how far the eye can see through telescopes with Zerodur mirrors. The presentations held by Dr. Yvonne Menke (SCHOTT) and Prof. Hideo Hosono (Tokyo Institute of Technology, Japan) illustrated how Petzoldt’s work for the benefit of optics went much further than glass-ceramics. Dr. Menke introduced opto-ceramics as a new optical material with extremely high refractive indexes. Prof. Hosono reported on his pioneering work aimed at consolidating optics and electronics in a single material class called transparent amorphous semi­conductors. Initial displays based on this are already available on the market.
Dr. Mark Davis (SCHOTT) had just discussed the underlying procedure of developing material classes on the drawing board so to speak on the basis of fundamental considerations in reference to Jürgen Petzoldt’s work. Thinking systematically while developing new material classes and having the courage to pursue these consistently were quite characteristic of him and ultimately made him one of the fathers of glass-ceramics. The speakers at this memorial colloquium impressively demonstrated that the potential that glass-ceramics still holds is far from being fully utilized. <|

Prof. Dr. rer. nat. Jürgen Petzoldt: Excellent researcher and successful entrepreneur

What is a glass-ceramic?