报告人简介：
同济大学功能材料研究所教授，现从事高温单相磁电、压电多重铁性功能材料物理和纳米铁电材料物理研究。曾主持国家自然科学基金青年基金和上海市自然科学基金各1项。个人荣获2004年度德国洪堡学者，2004-2006年度日本学术振兴会外国人特别研究员，2007 年获教育部新世纪优秀人才计划和上海市浦江人才计划等项目资助。
报告摘要：
Since 2011, materials genome approach has been speeded up applying to accelerate material innovations including pace of both discovery and deployment of advanced materials. The genome of material is atom and its electronic structure. The theoretical bases of materials genome approach are Periodic Table of Elements and Lattice Symmetry. Dalton’s atomic theory set foundation of atom of elements for chemical combination and physical structural phase transition---rearrangement of atom. Its purpose is to design novel materials in a predictable way other than in an alchemical (‘cooking’) way.
Perovskite-type ferroelectrics are one of most important functional materials, of which ferroelectric Curie temperature (TC) and piezoelectric response are closely dependent on its composition and lattice symmetry. In this talk, materials genome approach is used to analyze the determining factors of Curie temperature (TC) and piezoelectric constant (d33) in a quantitative way within the database of perovskite-type ferroelectrics. Two relationships of μ is reduced mass of ABO3 unit cell)1,2 and (ε33 is dielectric constant after poling ceramics)3,4 are obtained through fitting known data and interpreted well relating to mass and size of atom (‘genome of material’) within structural phase transition and dielectric theories, respectively. Based on the above two relationships and structural phase boundary for high piezoresponse, perovskite-type BiFeO3-Bi(Zn1/2Ti1/2)O3-PbTiO3 and BiFeO3-Bi(Zn1/2Ti1/2)O3- BaTiO3 ternary systems were chosen and experimentally studied as potential candidates for novel ferroelectrics with higher Curie temperature and piezoresponse than tungsten bronze-type PbNb2O6 and Aurivillius-type Bi4Ti3O12 ferroelectrics.3-5 The structural phase boundary was determined by powder X-ray diffraction and found strongly influenced by ceramic grain size. The structural phase boundary is intrinsically benefiting for high piezoresponse but residual internal stresses play extrinsic role to pin ferroelectric polarization switching and cause non-full poling treatment for the BZT-riched ceramics. Judged by , full piezoresponse was able to set in ceramics, excellent thermal and time aging stability of piezoelectric constant d33 were demonstrated contemporarily in BF-BZT-BT system.5 The residual internal stresses were argued resulting from one intermediate phase with negative thermal expansion coefficient recently discovered in BiFeO3-based ternary system and could be eliminated by post heat treatment.6 BF-BZT-BT and BF-BZT-PT are becoming promising candidate for future lead-free applications or high temperature applications because extended structural phase boundary provides big space to adjust piezoelectric performance and aging stabilities by changing composition. Our essay shows the data-driven materials genome approach much efficient in designing novel ferroelectric piezoceramic materials.
