论文标题
PBTE中的不中间的PB间隙
Off-centered Pb interstitials in PbTe
论文作者
论文摘要
在这项工作中，我们使用第一原理密度功能理论计算计算了PBTE中低对称性PB间隙的缺陷特性。我们打破了对中心的间质缺陷施加的对称性，并表明沿[111]方向的PB间隙缺陷的最低基态被偏心。 Due to the four multi-stable structures with low defect formation energies, the defect density of Pb interstitials is expected to be ~5.6 times larger than previous predictions when PbTe is synthesized at 900 K. In contrast to the on-centered Pbinterstitial, the off-centered Pb interstitials in PbTe can exhibit long-range lattice relaxation toward [111] direction beyond distance of 1 nm, indicating局部偶极子的潜在形成。该结果为PBTE的肺炎性超声性提供了另一种解释。
In this work, we calculate the defect properties of low-symmetry Pb interstitials in PbTe using first-principles density-functional theory calculations. We break the symmetry imposed on on-centered interstitial defects and show that the lowest ground state of Pb interstitial defects is off-centered along the [111] directions. Due to the four multi-stable structures with low defect formation energies, the defect density of Pb interstitials is expected to be ~5.6 times larger than previous predictions when PbTe is synthesized at 900 K. In contrast to the on-centered Pbinterstitial, the off-centered Pb interstitials in PbTe can exhibit long-range lattice relaxation toward [111] direction beyond distance of 1 nm, indicating the potential formation of weak local dipoles. This result provides an alternative explanation for the emphanitic anharmonicity of PbTe.
