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.
This work was financially supported by the Basic Science Research Program (Grant Nos. 2012R1A2A2A01046451 and 2012R1A1A2041628) through the National Research Foundation (NRF) of Korea.