Top electrode size effect on hysteresis loops in piezoresponse force microscopy of Pb(Zr,Ti)O 3-film on silicon structures

S. L. Bravina,
N. V. Morozovsky,
A. N. Morozovska,
J. Costecalde,
C. Soyer,
D. Remiens,
D. Deresmes

Інститут проблем матеріалознавства ім. І. М. Францевича НАН України , вул. Кржижановського 3, Київ, 03142, Україна
Journal of Applied Physics - Melville, USA: American Institute of Physics, 2012, #112


Experimental and theoretical studies of hysteresis loops in piezoresponse force microscopy (PFM) directed on elucidating the influence of top electrode lateral sizes on loop peculiarities were performed for Pt/Pb(Zr,Ti)O3/Pt/TiOx/SiO2/Si-substrate structures. The set of top Pt electrodes (50nm to 10μm of lateral size) was deposited on the Pb(ZrxTi1-x)O3 film (x=0.54, thickness ≈1μm) by RF magnetron sputtering. Under approaching the top electrode lateral size to the film thickness, the transition-like behaviour of PFM response amplitude and coercive tip voltage was observed. The existence of the critical value of dimensionless electrode size parameter γd/h≈1 (γ is the dielectric anisotropy factor, d is the electrode size parameter, and h is the film thickness) was interpreted in the framework of the model based on Landau-Ginzburg-Devonshire theory combined with the decoupling approximation subject to the nonlinear electric field dependence of the ferroelectric polarization and dielectric permittivity.