Abstract The unconventional Si-compatible ferroelectricity in hafnia-based systems, which becomes robust only at nanoscopic sizes, has attracted a lot of interest. While a metastable polar orthorhombic (o-) phase (Pca21) is widely regarded as the responsible phase for ferroelectricity, a higher energy polar rhombohedral (r-) phase is recently reported on epitaxial HfZrO4 (HZO) films grown on (001) SrTiO3 (R3m or R3), (0001) GaN (R3), and Si (111). Armed with results on these systems, here we report a systematic study leading toward identifying comprehensive global trends for stabilizing r-phase polymorphs in epitaxially grown HZO thin films (6 nm) on various substrates (perovskites, hexagonal and Si).

中文翻译：

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外延 Hf0.5Zr0.5O2 薄膜中极性菱面体相的稳定化指南

摘要 铪基系统中非常规的与硅相容的铁电体，仅在纳米级尺寸下才变得稳健，引起了人们的广泛兴趣。虽然亚稳极性正交 (o-) 相 (Pca21) 被广泛认为是铁电性的负责相，但最近在 (001) SrTiO3 上生长的外延 HfZrO4 (HZO) 薄膜上报道了更高能量的极性菱形 (r-) 相。 R3m 或 R3)、(0001) GaN (R3) 和 Si (111)。有了这些系统的结果，我们在这里报告了一项系统研究，该研究旨在确定在各种基板（钙钛矿、六方晶和 Si）上外延生长的 HZO 薄膜（6 nm）中稳定 r 相多晶型的综合全球趋势。