Surface potential relaxation of ferroelectric domain investigated by Kelvin probe force microscopy

We attempted to investigate the surface potential relaxation of ferroelectric thin film domain by using Kelvin probe force microscopy (KFM). To avoid charge suction phenomenon by a grounded tip, the offset voltage was applied to the base line of the pulse trace. It was found that the surface potential contrast decreased in terms of elapsed time. Spreading a charge around domain makes the surface potential contrast decrease. Coulomb force repulsion and retention loss contributed to the spreading of surface charges on the ferroelectric domain. These results help us understand surface potential relaxation of nanoscale ferroelectric domains.