Various types of lead-free ferroelectric ceramics have been developed in recent years due to environmental concerns over the use of lead-based materials such as lead zirconate titanate. Among these materials, perovskite-structured bismuth ferrite-barium titanate (BF-BT) and alkali niobate solid solutions show good potential as the basis for piezoelectric ultrasonic transducers operating at high temperatures, for applications in structural health monitoring and imaging. This PhD project focuses on the processing-structure-property relationships in these lead-free ferroelectric ceramics and coatings, with respect to their potential applications in high temperature piezoelectric transducer arrays.
The mechanisms that control the functional properties of BF-BT and alkali niobate ceramics are poorly understood at present. For example, it has been demonstrated recently that the control of processing procedures and the use of annealing and/or quenching procedures after sintering can exert a strong influence on their functional properties. Furthermore, the manufacturing methods and processing parameters that are necessary to prepare such materials in the form of thin films or coatings introduce further modifications of microstructure and performance. In this respect, aspects such as chemical non-stoichiometry, lattice defects, grain size, crystallinity, interfacial bonding and residual stress are well known as key controlling factors.
Selected compositions from the BF-BT and alkali niobate solid solution systems will be prepared in the form of bulk ceramics by solid state reaction and conventional high temperature sintering procedures. The underlying processing-structure-property relationships of these materials will be evaluated and suitable compositions identified on the basis of a high Curie point combined with useful piezoelectric activity. Subsequently, polycrystalline ‘thick film’ coatings will be manufactured by both air plasma spray and powder aerosol deposition methods, using the same precursor powders. Optimisation of processing parameters will enable the fabrication of dense and adherent piezoelectric coatings, which will be used as the basis for prototype ultrasonic devices.
Both IMRE, A*STAR and The Department of Materials at the University of Manchester have state-of-the-art facilities for characterizing the obtained powder and coating materials. In this project, XRD, DTA-TGA, TG-MS, SEM, TEM, SIMS, and XPS will be used to characterize the composition, morphology, and structure of the piezoelectric coatings, including developing understanding of the structural evolution. The dielectric, piezoelectric and ferroelectric properties will be characterised at both institutes, while work at IMRE will also include the design, fabrication and evaluation of the performance of ultrasonic transducers, measuring the electromechanical response up to 1.2 GHz when required using a laser scanning vibrometer.
Eligibility
Applicants must have obtained or be about to obtain a First or Upper Second class UK honours degree, or the equivalent qualifications gained outside the UK, in an appropriate area of science, engineering or technology.
Before you Apply
Applicants must make direct contact with preferred University of Manchester supervisors before applying. It is your responsibility to make arrangements to meet with potential supervisors, prior to submitting a formal online application.
How To Apply
To be considered for this project you MUST submit a formal online application form - full details on eligibility how to apply can be found on our website. On the online application form select PhD Materials Programme. Please ensure you include the full project title in your application, i.e. (A*STAR) Lead-free piezoelectric coatings for high temperature ultrasonic sensors.
Your application form must be accompanied by a number of supporting documents by the advertised deadlines. Without all the required documents submitted at the time of application, your application will not be processed and we cannot accept responsibility for late or missed deadlines. Incomplete applications will not be considered. If you have any queries regarding making an application please contact our admissions team [Email Address Removed]
Equality, Diversity and Inclusion
Equality, diversity and inclusion is fundamental to the success of The University of Manchester, and is at the heart of all of our activities. We know that diversity strengthens our research community, leading to enhanced research creativity, productivity and quality, and societal and economic impact. We actively encourage applicants from diverse career paths and backgrounds and from all sections of the community, regardless of age, disability, ethnicity, gender, gender expression, sexual orientation and transgender status.
We also support applications from those returning from a career break or other roles. We consider offering flexible study arrangements (including part-time: 50%, 60% or 80%, depending on the project/funder).
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