Events
Piezoelectricity at the Nanoscale
| Date: | Thursday 16 March 2006 14:00 - 16:00 |
| Location: | IRC Seminar Room |
Steve Dunn, Cranfield University
The world of piezoelectric materials covers applications as diverse as the injection system on a diesel powered articulated lorry to actuators used in digital cameras. There are a number of constants that ensure the operation of the piezoelectric material throughout and one is the concept of piezoelectricity and its independence on length scale. Recently a number of authors (Fridkin et al and Gruverman et al) have started to discuss the scalability of piezoelectricity and the origins of changes in the nature of piezoelectricity with size. The most common means of determining the effect of size on the ferroelectric property is to slice a large sample to make a small piezoelectric sample from the larger piece. This has shown that piezoelectric behaviour exists in samples that are <90nm in one dimension. The tools used to investigate the piezoelectric response are a modified form of scanning probe microscopy termed piezo-force-microscopy PFM. Here I will discuss our efforts to determine the influences of size on piezoelectric properties and also some of the projects that use PFM to modify or investigate the piezoelectric surface. We show that without the influence of clamping the magnitude of strain in a lead titanate sample can be around 1% and that it is possible to preferentially grow silver nanoislands on a predetermined pattern written into lead zirconate titanate. We also show that the influencing factors determining the growth of silver nanoislands is more complicated than previously thought by authors such as Kalinin and Bonnell.
