Ferroelectric Domain Scaling and Switching in Ultrathin BiFeO3 Films Deposited on Vicinal Substrates.

摘要

We report on electrically switchable polarization and ferroelectric domain scaling over a thickness range of 5-100 nm in BiFeO3 films deposited on 110 vicinal substrates. The BiFeO3 films of variable thickness were deposited with SrRuO3 bottom layer using the pulsed laser deposition technique. The domains are engineered into preferentially oriented patterns due to substrate vicinality along the 110 direction. The domain width scales closely with the square root of film thickness, in agreement with the Landau Lifschitz Kittel (LLK) law. Switching spectroscopy piezo-response force microscopy provides clear evidence for the ferroelectric switching behavior in all the films.