Husain Mudasser, Albalawi Hind, Al Huwayz Maryam, Khan Rajwali, Rahman Nasir
Department of Physics, University of Lakki Marwat 28420 Lakki Marwat KPK Pakistan
Department of Physics, College of Sciences, Princess Nourah Bint Abdulrahman University (PNU) PO Box 84428 Riyadh 11671 Saudi Arabia
RSC Adv. 2023 Aug 7;13(34):23716-23727. doi: 10.1039/d3ra04192a. eCollection 2023 Aug 4.
Using the density functional theory (DFT) method, we investigate the properties of LaXSi (X = Pt, Pd) half-Heusler compounds. To ensure the stability of both compounds, we employed two criteria: the Birch-Murnaghan equation of state and the negative formation energy. The evaluation of elastic constants (ECs) plays a crucial role in determining the mechanical stability of both compounds. Specifically, we ensure that the conditions C - C > 0, C > 0, C + 2C > 0, and > 0 are satisfied and exhibit mechanical anisotropy and ductility. The analysis of electronic properties clearly indicates that LaPtSi displays metallic behavior in both the spin-up and spin-down states. In the spin-up state of LaPdSi, a band gap is observed, which indicates its characteristic of being a half-metal. A comprehensive investigation of optical properties revealed that these compounds display notable absorption and optical conductivity at higher energy levels. Conversely, they exhibit transparency to incident photons at lower energy levels. Based on the findings, it can be concluded that these compounds are highly suitable for application in high-frequency UV devices. The thermoelectric properties clearly indicate that both materials exhibit high power factors, electrical conductivity, and figures of merit (), suggesting their potential as exceptional thermoelectric materials. The simulations conducted in this study consider the effect of on-site Coulomb interactions by incorporating the Hubbard U term within the GGA + U. Our findings contribute valuable insights that can facilitate further experimental investigations and provide comprehensive validation.
采用密度泛函理论（DFT）方法，我们研究了LaXSi（X = Pt，Pd）半赫斯勒化合物的性质。为确保这两种化合物的稳定性，我们采用了两个标准：Birch-Murnaghan状态方程和负形成能。弹性常数（ECs）的评估在确定这两种化合物的机械稳定性方面起着至关重要的作用。具体而言，我们确保满足C - C > 0、C > 0、C + 2C > 0和> 0的条件，并表现出机械各向异性和延展性。电子性质分析清楚地表明，LaPtSi在自旋向上和自旋向下状态下均表现出金属行为。在LaPdSi的自旋向上状态下，观察到一个带隙，这表明其半金属特性。对光学性质的全面研究表明，这些化合物在较高能级上表现出显著的吸收和光导率。相反，它们在较低能级上对入射光子表现出透明性。基于这些发现，可以得出结论，这些化合物非常适合应用于高频紫外器件。热电性质清楚地表明，这两种材料都表现出高功率因子、电导率和优值（），表明它们作为优异热电材料的潜力。本研究中进行的模拟通过在GGA + U中纳入哈伯德U项来考虑在位库仑相互作用的影响。我们的发现提供了有价值的见解，有助于进一步的实验研究并提供全面的验证。
