from    
to    
search  

 


清华大学材料科学与工程研究院《材料科学论坛》:近红外二区磷光成像
清华大学材料科学与工程研究院《材料科学论坛》:四方Sr4Al2O7:一种用于制备高质量...
Massive Particles at Spatial Infinity
An update on holography of information (Review)
报告题目:
Relaxor Ferroelectric Materials: Design and Application
 报告人:
Prof. Shujun Zhang
Shujun Zhang is Professor at ISEM, AIIM, University of Wollongong, prior to
which, he was Professor at MatSE and Senior Scientist at Materials Research
Institute of The Pennsylvania State University, USA.
报告时间:
2019-12-09 10:00
报告地点:
高压馆205A
主办单位:
电机系
  简介:

Perovskite ferroelectric materials are at the heart of numerous electronic devices,

such as imaging transducer, piezoelectric sensors, energy harvesting and energy

storage capacitors, to name a few.

Relaxor-PT ferroelectrics show superior dielectric/piezoelectric properties,

outperforming conventional ferroelectric PZTs, which greatly benefit medical

ultrasound imaging. The good properties of relaxor-PT based materials are inherently

associated with their unique local structural heterogeneity: the existence of nanoscale

heterogeneous regions that coexists with normal ferroelectric domains. The

contribution of these local structures has been theoretically modelled to be the origin

of the ultrahigh dielectric and piezoelectric activities of relaxor based perovskite

ferroelectric crystals, accounting for 50-80% of their respective room temperature

values. Based on the paradigm, recent developments have experimentally confirmed

that modest changes in the polarizability of local structure, can be regarded as “seeds”

to further enhance the dielectric properties of ABO3 perovskite solid solutions. The

modified polycrystalline ceramics and crystals exhibit ultrahigh dielectric and

piezoelectric properties, with high piezoelectric coefficient of 4000 pC/N. In addition,

the energy storage performance of the local structure tuned perovskite ferroelectrics is

also greatly enhanced, with energy density of >9 J/cc (20 microns ceramic layer) and

energy efficiency of >90%. The relationship between local structure and macroscopic

properties has been established, try to understand the impact of local structure on

dielectric properties, to explore high performance ferroelectric materials for energy

harvesting and energy storage applications.


今日相关信息
Bridging the Competency Gap: Using Wo...
第358期“工物学术论坛”:非平衡态射频放...
非传统反应位点的精准官能团化
 
同类别相关信息
Integrating Generation Capacity Exp...
对新型电力系统演进趋势的认识
跨文化传播政治经济研究视野中的网络时代...
Next generation power devices: chal...
关于提升电力半导体器件短时过载能力及其...
学术活动