Room-temperature ferroelectricity in SrTiO3 nanodots array formed by an ac-bias field

Abstract

In its pure unstressed form, SrTiO3 (STO) remains quantum paraelectric down to 0 K. Herein, we demonstrate the ferroelectric STO nanodots array embodied by exploiting the idea of oxygen-vacancy-promoted ferroelectricity. First-principles calculations clearly support this idea. To practically activate the oxygen vacancies needed for the revelation of room-temperature ferroelectricity, we have applied an ac-bias field with various switching cycles at a conducting atomic-force-microscope tip. The STO nanodots with optimum polarization-switching characteristics have been implemented by suitably trading-off between the oxygen-vacancy-promoted polarization and the increasing leakage current with the switching cycle. (C) 2013 AIP Publishing LLC.