A systematic theoretical investigation is carried out on the possible piezoelectric effect in the half-Heusler FeVX (X = P, As, Sb) compounds crystallizing in the cubic MgAgAs-type structure C1_b by combining density functional theory (DFT) and perturbation theory (DFPT) based on the pseudopotential plane wave (PP-PW) method implemented in the ABINIT code. The ground-state properties such as the lattice constants, and the bulk modulus and its pressure derivative are obtained using both the local density approximation and the generalized gradient approximation for the exchange–correlation functional, and the results are compared with other studies. The results for the electronic properties reveal that all the compounds exhibit semiconducting behavior with a narrow indirect bandgap. In addition, the elastic, dielectric, and piezoelectric constants are computed using density functional perturbation theory. The title compounds are found to exhibit a good electromechanical coupling coefficient (k₁₄). No experimental or theoretical data are available for their piezoelectric properties. Thus, the results of this study can be considered to represent theoretical predictions of the properties of new piezoelectric half-Heusler compounds that can be selected based on the values of their piezoelectric coefficient (e₁₄), which are greater than the value of 0.16 C/m² measured empirically for GaAs. Finally, the results presented herein shed light on the use of such piezoelectricity as a possible effect in various applications such as micromechanical actuators, sensors, and self-powered devices.

甲系统的理论调查在半霍伊斯勒钒铁可能的压电效应进行X（X  = P，砷，锑）化合物中的立方MgAgAs型结构结晶C1 _b通过将密度泛函理论（DFT）和微扰理论（DFPT）结合起来，基于在ABINIT代码中实现的伪电位平面波（PP-PW）方法。使用交换相关函数的局部密度近似和广义梯度近似来获得基态属性，例如晶格常数，体积模量及其压力导数，并将其与其他研究进行比较。电子性质的结果表明，所有化合物均表现出具有窄的间接带隙的半导体行为。此外，弹性，介电和压电常数是使用密度泛函微扰理论计算的。发现标题化合物具有良好的机电耦合系数（k ₁₄）。没有关于压电性能的实验或理论数据。因此，该研究的结果可被视为代表了新的压电半霍斯勒化合物的性能的理论预测，这些化合物可基于其压电系数（e ₁₄）的值进行选择，该值大于0.16 C Gam的经验值/ m ²。最后，本文介绍的结果阐明了这种压电技术在各种应用（例如微机械致动器，传感器和自供电设备）中的可能作用。