Epitaxial ferroelectric Pb(Zr0.2Ti0.8)O3 thin films on silicon: physical properties and applications

Alessia Sambri (Genf)

The family of complex oxides displays a wide variety of electronic properties ranging from ferroelectricity to ferromagnetism and superconductivity. This richness is often due to strong electronic correlations, which determine complex phase diagrams and competing ground states. These electronic states are very sensitive to external parameters as electric, magnetic or elastic fields. Since nowadays it is possible to control the growth of epitaxial thin films of such compounds on atomic scale, their properties can be modified through the epitaxial strain, a technique called strain engineering [1,2]. In this presentation I will discuss the physical properties of Pb(Zr0.2Ti0.8)O3 thin films grown on silicon wafers using SrTiO3 as chemical and structural buffer. In particular, I will focus on the effect of the epitaxial strain on the critical temperature of the ferroelectric-paraelectric phase transition. In the second part of the talk, I will present the employ of these piezoelectric films on silicon for microelectromechanical system (MEMS), describing the static and dynamic properties of piezoelectric membranes and cantilevers based on such heterostrucures [3].

[1] Schlom, D. G.; Chen, L.-Q.; Eom, C.-B.; Rabe, K. M.; Streiffer, S. K. & Triscone, J.-M. “Strain Tuning of Ferroelectric Thin Films” Annual Review of Materials Research 37, 589-626 (2007).

[2] Gariglio, S.; Stucki, N.; Triscone, J.-M. & Triscone, G. “Strain relaxation and critical temperature in epitaxial ferroelectric Pb(Zr0.2Ti0.8)O3 thin films” Appl. Phys. Lett. 90, 202905-3 (2007).

[3] Isarakorn, D.; Sambri, A.; Janphuang, P.; Briand, D.; Gariglio, S.; Triscone, J.-M.; Guy, F.; Reiner, J. W.; Ahn, C. H.; de Rooij, N F. “Epitaxial piezoelectric MEMS on silicon” J. Micromech. Microeng. 20 (2010) (in press).

 

(Seminarraum I)

---