BaTiO₃ exhibits several functional properties, such as high dielectric constant, large Pockels coefficient, and strong ferroelectricity/piezoelectricity. These properties can be used for a variety of applications, such as ferroelectric tunnel junctions in non-volatile memory devices. To achieve large-scale integration of BaTiO₃, however, one requires the synthesis of high-quality BaTiO₃ films at low temperatures in order to be compatible with the thermal budget of electronic processes in use today. Here, we describe the synthesis of BaTiO₃ thin films by molecular beam epitaxy and find that coherently strained and ferroelectric BaTiO₃ can be grown at temperatures as low as 310 °C. Using reflection high energy diffraction, we demonstrate a surface mobility of BaO and TiO₂ adatoms that is high enough to promote ferroelectric crystal growth at low temperatures. A clear ferroelectric polarization switching is observed using piezoresponse force microscopy. Our results pave the way toward large-scale integration of ferroelectric BaTiO₃ with mainstream electronics platforms.

中文翻译：

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外延铁电BaTiO3的低温生长

BaTiO ₃表现出多种功能特性，例如高介电常数，大普克尔斯系数和强铁电/压电。这些特性可用于多种应用，例如非易失性存储设备中的铁电隧道结。然而，为了实现BaTiO ₃的大规模集成，人们需要在低温下合成高质量的BaTiO ₃膜，以便与当今使用的电子工艺的热预算兼容。在这里，我们描述了通过分子束外延合成BaTiO ₃薄膜，并发现相干应变和铁电化的BaTiO ₃可以在低至310°C的温度下生长。使用反射高能衍射，我们证明了BaO和TiO ₂原子的表面迁移率足够高，可以促进低温下铁电晶体的生长。使用压电响应力显微镜观察到清晰的铁电极化转换。我们的结果为铁电BaTiO ₃与主流电子平台的大规模集成铺平了道路。