主讲人：晏海学 博士（Reader）（伦敦大学玛丽女王学院）

题目：Dielectric behavior of high entropy ferroelectric ceramics

时间：2024年4月16日（周二）下午14：30

地 点：理工楼1226

联系人：贾成龙

报告摘要：

High entropy materials represent interesting properties, such as a preference to form single phase materials, lattice distortions, small grain sized microstructure and unexpected properties that go beyond the rule of mixtures of their constituent components. Recently three groups of high entropy ceramics, including perovskite structured ABO₃ferroelectrics, Aurivillius phase ferroelectrics and perovskite layer structured (PLS) ferroelectrics, were successfully prepared and characterized [1-3]. In this talk, we will discuss the high entropy effect on structures and properties in the three groups of ferroelectric ceramics.

References：

[1] Xiong et al, J. Euro. Ceram Soc. 41, 2979–2985 (2021); Appl. Phys. Lett. 121, 112901 (2022).

[2] Zhang et al, Materials and Design 200, 109447 (2021); Acta Materialia 229, 117815 (2022).

[3] Hu et al, J. Euro. Ceram. Soc. 43, 177–182 (2023).

个人简介：

Dr Haixue Yan is a Reader in Materials Science and Engineering at Queen Mary University of London (QMUL). He is also an Appeals Panel Chair at QMUL. He is an expert on high temperature piezoelectric, Spark Plasma Sintering (SPS), phase transitions in ferroelectrics and PVDF-based ferroelectric polymers. He reported for the first-time ferroelectricity and piezoelectricity in layer-structured A₂B₂O₇ceramics with super-high Curie points (>1450°C). This work has produced a step-change in the operating temperature of piezoelectric sensors. His work on SPS has demonstrated that nano particles can work as building blocks during fast sintering. His work on ferroelectric characterization has provided evidences to answer open questions on phase transitions in lead-free ferroelectrics including Bi_0.5Na_0.5TiO₃, NaNbO₃and AgNbO₃-based dielectrics for energy storage applications. Recently his research has focused on high entropy ferroelectric ceramics for dielectric and/or piezoelectric applications. He is on the editorial board of Scientific Reports, Advance in Applied Ceramics, Material Research Bulletin and Journal of Advanced Ceramics. Dr. Yan is an FIMMM and FRSC. He has 9 patents and >230 publications in peer-reviewed journals with an H-index of 55. He regularly gives invited/keynote talks in international conferences.