论文标题
SE掺杂在最近合成的Nains2-XSEX固定溶液中对通过第一原理方法研究的潜在热机械应用的影响
Influence of Se doping in recently synthesized NaInS2-xSex solid solutions for potential thermo-mechanical applications studied via first-principles method
论文作者
论文摘要
在目前的工作中，已经使用密度功能理论研究了Nains2-XSEX（X = 0、0.5、1.0、1.5和2.0）的Nains2-XSEX（X = 0、0.5、1.0、1.5和2.0）的结构和机械性能。此外，随着SE含量的变化，已经研究了Nains2-XSEX的弹性各向异性指数和硬度。所有正在研究的化合物的机械稳定性已得到证实。剪切与散装模量（g/b）的比率很低，表明Nains2-XSEX（X = 0.5和1.5）化合物具有损伤（延性）特性，而其余组合物本质上都是脆性的。预测的硬度（h）值也受到以下顺序的SE含量的影响：h（nainsse）> h（nains2）> h（nainse2）> h（nains1.5se0.5）> h（Nains0.5Se1.5）。所有各向异性指标都表明Nains2-XSEX化合物本质上是各向异性的。 Mulliken键种群分析表明，当S代替SE时，INS/SE键的共价程度会降低。通过考虑化合物的平均原子量（M/N）和平均键强度，成功地解释了低DEBYE温度（θD）和低最小导热率（KMIN）的起源。还使用准谐波Debye模型估算热能（CV，CP）和线性热膨胀系数（α）的温度依赖性并进行了讨论。 Kmin，θd和α的低值以及耐受的行为清楚地表明，Nains2-XSEX（X = 0.5和1.5）化合物可以用作高温应用的有希望的热屏障涂层材料。
In the present work, the structural and hitherto unexplored thermal and mechanical properties of NaInS2-xSex (x = 0, 0.5, 1.0, 1.5 and 2.0) compounds have been studied using the density functional theory. Besides, the elastic anisotropy indices and hardnesses of NaInS2-xSex have been investigated as Se content is varied. The mechanical stability of all the compounds under study has been confirmed. The ratio of shear to bulk modulus (G/B) is low suggesting that the NaInS2-xSex (x = 0.5 and 1.5) compounds exhibit damage tolerant (ductility) properties while rest of the compositions are brittle in nature. The predicted hardness (H) values are also influenced with the Se content in the following order: H (NaInSSe) > H (NaInS2) > H (NaInSe2) > H (NaInS1.5Se0.5) > H (NaInS0.5Se1.5). All the anisotropic indices under study indicate that NaInS2-xSex compounds are anisotropic in nature. The Mulliken bond population analysis suggests that the degree of covalency of In-S/Se bonds decreases when S is substituted by Se. The origin of low Debye temperature (ΘD) and low minimum thermal conductivity (Kmin) have been successfully explained by considering the mean atomic weight (M/n) and average bond strength of the compounds. Temperature dependence of heat capacities (Cv, Cp) and linear thermal expansion coefficient (α ) are also estimated using the quasi-harmonic Debye model and discussed. The low values of Kmin, ΘD and α and damage tolerant behavior clearly indicate that the NaInS2-xSex (x = 0.5 and 1.5) compounds can be used as promising thermal barrier coating materials for high temperature applications.
