This manuscript demonstrates ferroelectricity in B-substituted AlN thin films and a complementary set of first-principles calculations to understand their structure-property relationships. ${\mathrm{Al}}_{1–x}{\mathrm{B}}_x\mathrm{N}$ films are grown by dual-cathode reactive magnetron sputtering on $\left(110\right)\mathrm{W}/\left(001\right){\mathrm{Al}}_2{\mathrm{O}}_3$ substrates at 300°C at compositions spanning $x=0$ to $x=0.20$. X-ray diffraction studies indicate a decrease in both the $c$ and $a$ lattice parameters with increasing B concentration, resulting in a decrease in unit cell volume and a constant $c$/$a$ axial ratio of 1.60 over this composition range. Films with $0.02\le x\le 0.15$ display ferroelectric switching with remanent polarizations exceeding $125\mu \mathrm{C}\mathrm{c}{\mathrm{m}}^{–2}$ while maintaining band gap energies of $>5.2\mathrm{eV}$. The large band gap allows low frequency hysteresis measurement (200 Hz) with modest leakage contributions. At B concentrations of $x>0.15$, $c$-axis orientation deteriorates and ferroelectric behavior is degraded. Density-functional theory calculations corroborate the structural observations and provide predictions for the wurtzite $u$ parameter, polarization reversal magnitudes, and composition-dependent coercive fields.

中文翻译：

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硼取代的氮化铝薄膜中的铁电

该手稿证明了B取代的AlN薄膜中的铁电性以及一组补充的第一性原理计算，以了解它们的结构-特性关系。 ${铝}_{\mathrm{1个}–X}{\mathrm{乙}}_X\mathrm{ñ}$ 薄膜通过双阴极反应磁控溅射在 $（110）\mathrm{w\; ^}/（001）{铝}_{\mathrm{2个}}{\mathrm{Ø}}_3$ 底物在300°C的温度范围内 $X=0$ 至 $X=0.20$。X射线衍射研究表明，$C$ 和 $\mathrm{一种}$ B浓度增加时的晶格参数，导致晶胞体积减小和常数 $C$/$\mathrm{一种}$在此成分范围内的轴向比为1.60。电影与$0.02\le X\le 0.15$ 显示铁电开关，剩余极化强度超过 $125\mu \mathrm{C}\mathrm{C}{\mathrm{米}}^{–\mathrm{2个}}$ 同时保持带隙能为 $>5.2\mathrm{电子伏特}$。较大的带隙可实现低频磁滞测量（200 Hz），且泄漏量适中。在B浓度下$X>0.15$， $C$轴取向变差，铁电性能变差。密度泛函理论计算证实了结构观察并为纤锌矿提供了预测$ü$ 参数，极化反转幅度和成分相关的矫顽场。