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arXiv · 2011.06082

Controlling ferroelectric hysteresis offsets in PbTiO$_{3}$ based superlattices

Simon Divilov·Hsiang-Chun Hsing·Mohammed Humed Yusuf·Anna Gura·Joseph A. Garlow·Myung-Geun Han·Massimiliano Stengel·John Bonini·Premala Chandra·Karin M. Rabe·Marivi Fernandez Serra·Matthew Dawber
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Abstract

Ferroelectric materials are characterized by degenerate ground states with multiple polarization directions. In a ferroelectric capacitor this should manifest as equally favourable up and down polarization states. However, this ideal behavior is rarely observed in ferroelectric thin films and superlattice devices, which generally exhibit a built-in bias which favors one polarization state over the other. Often this polarization asymmetry can be attributed to the electrodes. In this study we examine bias in PbTiO$_3$-based ferroelectric superlattices that is not due to the electrodes, but rather to the nature of the defects that form at the interfaces during growth. Using a combination of experiments and first-principles simulations, we are able to explain the sign of the observed built-in bias and its evolution with composition. Our insights allow us to design devices with zero built-in bias by controlling the composition and periodicity of the superlattices.

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Simon Divilov, Hsiang-Chun Hsing, Mohammed Humed Yusuf, Anna Gura, Joseph A. Garlow, Myung-Geun Han, Massimiliano Stengel, John Bonini, Premala Chandra, Karin M. Rabe, Marivi Fernandez Serra, Matthew Dawber. 2020-11-11. Controlling ferroelectric hysteresis offsets in PbTiO$_{3}$ based superlattices. https://arxiv.org/abs/2011.06082

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