Title: Origin of enhanced electromechanical coupling in YbAlN alloy nitrides Show Chinese title

Title: YbAlN合金氮化物中增强的机电耦合效应的起源

Abstract: Our experiments demonstrate that alloying the cubic--phase YbN into the wurtzite--phase AlN results in clear mechanical softening and enhanced electromechanical coupling of AlN. The first principle calculations reproduce experimental results well, and predict a maximum of 270% increase in electromechanical coupling coefficient caused by 1) enhanced piezoelectric response induced by the local strain of Yb ions and 2) structural flexibility of the YbAlN alloy. Additionally, our calculations reveal the existence of repulsion among tetrahedral Yb$^{3+}$ sites, which suppresses further mechanical softening for YbAlN at high Yb concentrations. Show Chinese abstract

Abstract: 我们的实验表明，将立方相的YbN合金化到纤锌矿相的AlN中会导致明显的机械软化和AlN的增强压电耦合。 第一性原理计算很好地再现了实验结果，并预测由于1）Yb离子的局部应变引起的压电响应增强以及2）YbAlN合金的结构灵活性，导致压电耦合系数最大增加270%。 此外，我们的计算揭示了四面体Yb$^{3+}$站点之间的排斥作用，这会抑制高Yb浓度下YbAlN的进一步机械软化。