Scaling laws in PZT thin films grown on Si(001) and Nb-Doped SrTiO3(001) substrates

Abstract

A dynamic scaling and kinetic roughening study was done on digitized atomic force microscope (AFM) images of Pb(Zr 0.52 , Ti 0.48 )O 3 (PZT) thin films. The films were grown on Si(001) and Nb − SrTiO 3 (001) (STNO) substrates via rf-sputtering technique at high oxygen pressures at substrate temperatures of 600 o C by varying the deposition time and keeping other growth parameters fixed. By using a specific self-designed algorithm, we can extract from digitized 512-pixel resolution AFM-images, quantitative values of roughness parameters, i.e., interface width (σ ( )), lateral correlation length (ξ || ) and, roughness exponent (α). Herein, we report on the sputter-time deposition dependence of the parameters describing roughness for both kinds of substrates. We report α-values for different time depositions (between 15 and 60 minutes) close to 0.55 for Si substrates and 0.63 for Nb − SrTiO 3 substrates, indicating that the surface becomes more correlated in STNO substrates. The α-values are associated to the Lai-Das-Sarma-Villain model.

Fenómenos interfaciales en multicapas y superredes magnéticas: revisión y perspectivas

“…Este concepto es importante cuando queremos medir cuantitativamente la rugosidad interfacial. En un análisis estadístico de imágenes de microscopía de fuerza atómica en películas delgadas de materiales óxidos, se detectó la naturaleza fractal de las interfaces (Ramírez et al, 2004;Ramírez et al, 2006). El análisis cuantitativo de patrones de difracción requiere una comparación con patrones simulados de modelos que consideren, entre otros factores, la estructura de defectos cristalinos en la interfaz (Fullerton et al, 1992).…”

Surface morphology effects on polarization switching in nanoscale ferroelectrics

“…As film thicknesses become increasingly small, it is expected that surface effects will become increasingly important. In general, the surfaces of ferroelectric thin films are not atomically flat but commonly exhibit nanoscale roughness [6,7].…”