应理学院数理青年教师联合会、田浩教授邀请，德国国家科学与工程院院士Jürgen Rödel教授来我校进行学术交流，开展无铅压电材料相关讲座，欢迎校内感兴趣的师生参加。

题目：Lead-free piezoceramics: From basic science to application

时间：2017年4月25日9：00~10：00

地点：活动中心227

Lead-free piezoceramics: From basic science to application Jürgen Rödel Institute of Materials Science, Technische Universität Darmstadt

While the traditional materials of choice for piezoelectric devices over the past 60 years were lead-based perovskite ceramics, the environmental- and health-concerns, supported by governmental regulations, triggered the search for new lead-free alternatives . During the past 10 years the research output rose from 10 to 400 publications per year with China and Japan leading, Europe accounting for 10 % of the total quantity and the US only showing very select activities. In addition, a number of companies invested large sums into research and they aim at solid financial return. Some of them produced material reproducibly in 100 kg batches and select areas were identified, where lead-free piezoceramics have an advantage to lead-containing piezoceramics. As a result, the first products started to appear at the market place.

The aim of this contribution is to review the global situation and present scientific challenges and advancements. It is now apparent, that lead-free piezoceramics will come, but with different potency for the different applications concerned.

In the interest of time, I will focus on NBT-xBT piezoceramics. I will introduce their properties and will discuss recent work on the local structure. After a discussion of orientation-dependent properties in single crystals, I will specifically highlight significant recent discoveries in the field of NBT-BT composites. They allow to reduce the electric driving field, enhance the depolarization temperature and provide a new means of making the material harder.

In the end I provide examples for application relevant work on electrical fatigue and on fracture toughness of NBT-xBT piezoceramics.

Jürgen Rödel教授简介：

Jürgen Rödel教授毕业于美国加州大学伯克利分校，目前是达姆施塔特工业大学主管科研的副校长，同时是材料与地球科学系的学科带头人。他主要的研究方向为功能陶瓷材料，发表过280余篇学术论文，被引用10000余次，H因子51。2009年荣获德国科技最高奖“莱布尼茨奖”（Leibniz Prize of the Deutsche Forschungsgemeinschaft），2014年当选德国国家科学与工程院院士（Member of German National Academy of Science and Engineering）。

Rödel教授获得的主要荣誉有：

Ø2003，美国陶瓷学会院士Fellow of the American Ceramic Society (USA)

Ø2007，世界陶瓷科学院院士Member of World Academy of Ceramics

Ø2009，德国科学基金会莱布尼茨奖Leibniz Prize of the Deutsche Forschungsgemeinschaft

Ø2014，德国国家科学与工程院院士Member of German National Academy of Science and Engineering (acatech)