Generation IV Piezoelectric Single Crystals

Lead Research Organisation: University of Leeds
Department Name: Chemical and Process Engineering

Abstract

This project will explore novel compositions of piezoelectric single crystals for use in sonar and medical imaging devices. The candidate will identify materials systems with greater flexibility in tailoring properties than the current commercial systems based on Pb(Mg, Nb)O3-PbTiO3, which suffer from low maximum operational temperatures. Of particular interest as new materials are pseudo-ternary perovskite compounds based around the rhombohedral tetragonal (R-T) phase boundary in BiFeO3-PbTiO3. Potential alloying compounds include Bi(Mg, Ti)O3, Bi(Zn, Ti)O3 and MFeO3, where M is a 3+ ion such as La, Gd, Nd, etc.

The candidate will explore these systems initially in ceramic form, using conventional mixed oxide processing, to identify compositions with appropriate combinations of Tc and proximity to a R-T phase boundary, before carrying out growth trials using the Bridgman method. It is expected that the project will identify at least one new family of single crystals from which a number of compositions with properties tailored to different transducer applications will be grown and characterized.

Publications

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Studentship Projects

Project Reference Relationship Related To Start End Student Name
EP/N509243/1 01/10/2015 31/12/2021
1632338 Studentship EP/N509243/1 01/10/2015 30/09/2019 Thomas Elliot Hooper
 
Description Through mathematical modelling, it has been possible to highlight outstanding candidates that possess a much higher sensitivity to external stimuli compared to other piezoelectric materials (ie materials that can convert mechanical energy into electrical energy and vice versa). The findings of this modelling suggest that the solid solution of bismuth ferrite (BiFeO3) and lead titanate (PbTiO3) in single crystal form exhibits a "sensitivity coefficient" more than twice the value of previously characterised materials. Furthermore, this material is of significant interest in applications which require harsh environments as the temperature in which it loses its piezoelectric properties (~630 degrees celsius) is significantly larger than market dominant piezoelectric materials which are often limited to 200-250 degrees celsius.
Exploitation Route The results of mathematical modelling highlight bismuth ferrite lead titanate as an outstanding candidate for high sensitivity piezoelectrics, which may pave the way for others to experimentally validate this hypothesis, and incorporate these materials into devices to be used in passive sensors used in the fishing, security, automotive and oil and gas industries as listening devices.
Sectors Aerospace, Defence and Marine,Digital/Communication/Information Technologies (including Software),Electronics,Security and Diplomacy