ABSTRACT In this work, the structural, electronic, and dynamical properties of novel half-Heusler (HH) alloy AlNiP are studied by applying first-principles density functional theory (DFT). The structural properties of AlNiP in the LiAlSi-type crystal structure with three different phases (α-phase, β-phase, and γ-phase) in different atomic arrangements are explored. The ‘γ-phase’ of AlNiP is found to be energetically stable among three. Moreover, the calculated ferromagnetic (FM), non-magnetic (NM) and anti-ferromagnetic (AFM) state for AlNiP favours the ‘NM’ state. The overlapping of the valence band and conduction band signifies the metallic characteristics of the alloy at 0 GPa and high pressure 38 GPa. The lattice dynamics of novel HH alloy AlNiP have also been investigated by applying DFT followed by density functional perturbation theory (DFPT). The phonon calculation suggests the face-centred cubic phase of HH alloy AlNiP is stable at ambient condition and also at high pressure of 38 GPa. For the confirmation of this stability, the phonon density of states has also been calculated at zero and higher value of pressure. The calculated results are further interpreted in the light of the similar type of alloys.

中文翻译：

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新型AlNiP半赫斯勒合金结构、电子和晶格动力学特性的理论研究

摘要 在这项工作中，应用第一性原理密度泛函理论 (DFT) 研究了新型半赫斯勒 (HH) 合金 AlNiP 的结构、电子和动力学特性。探索了 AlNiP 在具有不同原子排列的三种不同相（α 相、β 相和 γ 相）的 LiAlSi 型晶体结构中的结构特性。发现 AlNiP 的“γ 相”在三者中能量稳定。此外，计算出的 AlNiP 的铁磁 (FM)、非磁 (NM) 和反铁磁 (AFM) 状态有利于“NM”状态。价带和导带的重叠表示合金在 0 GPa 和高压 38 GPa 下的金属特性。还通过应用 DFT 和密度泛函微扰理论 (DFPT) 研究了新型 HH 合金 AlNiP 的晶格动力学。声子计算表明 HH 合金 AlNiP 的面心立方相在环境条件下和 38 GPa 的高压下也是稳定的。为了确认这种稳定性，还在零和更高压力值下计算了声子态密度。计算结果根据合金的相似类型进一步解释。