Contacts: Nini Pryds, (nipr@ dtu.dk) tel: 4677 5752, and Vincenzo Esposito (vies@dtu.dk) DTU Energy, Functional-Electronic Materials (EFM).
Piezoelectrics, the change in material’s static dimension when an external electric field is applied and vice versa, have widespread use in today’s sensor and actuator technologies. However, most commercially available piezoelectric materials, e.g., Pb [ZrxTi1-x] O3 (PZT), are comprised of more than 60 percent lead (Pb) (wt.%). Due to its harmful effects, the use of Pb will be restricted by the he European RoHS directive. There is thus a strong need to identify new lead-free materials with comparable properties to those of PZT. The basic idea of this subproject is to investigate gadolinium (Gd)-doped ceria (Ce0.8Gd0.2O1.9, CGO) an interesting material exhibits giant electrostriction or shape change on the application of electric field, as a potential material for piezoelectric actuators.
The giant electrostriction effect can only be best achieved in thin film samples. Thin film preparation, electrode choice and their combination with silicon-based technologies are the first steps in realizing these materials in applications.
The films will be prepared using Pulsed Laser Deposition (PLD) a simple but effective technique to grow high quality oxide films, which is available at DTU Energy. The electrostriction effect will be investigated by measuring the shaking amplitude of a thin sheet sample upon applying a voltage across the sample.
The task of this project: You should first learn the physical basis for the technique, and then start to prepare and characterize your own thin films to realize the electrostriction effect. Once the films are ready, the deflection of these films upon the application of voltage will be investigated. In this project you will develop the first step in fabricating ceria-based actuating devices which will in the future be candidate to replace the conventional piezoelectric materials. We also targeting that in the end of the project you will take part in writing short article on the material fabrication and behaviour.