Читать книгу Lead-Free Piezoelectric Materials - Jing-Feng Li - Страница 10

Foreword by Professor Longtu Li

Piezoelectric materials possess the functionality of interconversion between electrical energy and mechanical energy, which have been widely used in electronic information, communication, automobile, military defense, aeronautics and space technology, medical diagnostics, energy storage and harvesting, artificial intelligence, and advanced manufacturing, among other applications. The market‐dominating piezoelectric ceramics are based on the Pb(Zr,Ti)O₃ (abbreviated as PZT) system, which is a big family with diverse chemical modifications designed for specific applications. PZT‐based ceramics possess comprehensive excellent properties, but its environmental incompatibility has generated increasing concerns since the beginning of the twenty‐first century. In addition, the European Union's legislation about Restriction of the use of certain Hazardous Substances (RoHS) in electrical and electronic equipment has accelerated the research and development of high‐performance lead‐free piezoelectric ceramics.

Piezoelectric ceramics and device applications have been one of the key research directions in the State‐Key Laboratory of New Ceramics and Fine Processing, Tsinghua University. At Tsinghua University, our research groups mainly focused on lead‐based piezoelectric ceramics and their applications before the twenty‐first century. Since the new century I became deeply interested in lead‐free piezoelectrics and have been heavily involved in the related research activities with several research groups within our state‐key laboratory. Among them, Prof. Jing‐Feng Li is the leader of the biggest research group working on lead‐free piezoelectric ceramics since 2002 when he moved to Tsinghua University from Tohoku University. With the financial support from the National Natural Science Foundation and the Ministry of Science and Technology of China, Tsinghua University and Toyota Motor Corporation, Prof. Jing‐Feng Li has been focusing on the (K,Na)NbO₃ lead‐free piezoelectric system and made substantial progress in numerous research areas, including sintering process, characterization and manipulation of hierarchical structure, chemical modification, and piezoelectricity enhancement mechanism, etc. Because of these impressive achievements, he has received the first‐class science and technology award from the Chinese Ceramic Society. Meanwhile, a start‐up company was also founded by his former students quite recently to promote the mass production and industrial applications of the high‐performance (K,Na)NbO₃‐based piezoceramics.

Writing a book especially in foreign language is not easy, which requires not only extensive knowledge about the field but also hard work and perseverance. Prof. Jing‐Feng Li has spent more than two years to complete this monograph about lead‐free piezoelectric materials, which adds his contributions to the field of ferroelectrics and piezoelectrics. This book has systematically compiled the research progress of several promising lead‐free piezoelectric systems, which could synchronize the perspectives of researchers from both academia and industry over the development of lead‐free piezoelectric systems, and will undoubtedly inspire future research endeavors in both fundamental and application‐oriented studies.

Owing to the increasing emphasis and requirement of green manufacturing and environmental friendly materials, study on the lead‐free piezoelectric ceramics has become more popular around the world. Many significant results and findings of theoretical and experimental studies related to lead‐free piezoelectric ceramics have been published. This book has captured some of the latest developments and most recent advancements in this exciting field. I hope and believe that readers will find interesting and useful information from this book.

Longtu Li

Professor, Tsinghua University

Member of Chinese Academy of Engineering