Strain effects on electronic and dynamical properties of half-Heusler semiconductors: insights from Meta-GGA

Author:

Mellah Djallal EddineORCID,Demmouche Kamel,Bezzerga Djamel

Abstract

Abstract In this study, we investigated the effects of mechanical strain, including both tensile and compressive strains, on the electronic properties and dynamical stability of two ternary half-Heusler compounds: TiIrSb and ZrIrSb. We employed the plan wave pseudo-potential method (PW-PP) within the density functional theory (DFT) framework. Our calculations were performed using both the GGA-PBE and Meta-GGA-SCAN approximations. Furthermore, to compute the phonon dispersion, we employed the R2SCAN functional instead of SCAN for both compounds, addressing numerical challenges encountered with the latter. In the absence of strain, our calculations revealed that both compounds exhibit semiconducting behavior, featuring an indirect band gap at identical locations in the Brillouin Zone. Notably, the SCAN functional consistently predicted a larger band gap compared to the corresponding values obtained with PBE for both compounds. Specifically, the band gap expanded significantly, creating a noticeable separation between the valence and conduction bands. For TiIrSb, it increased from 0.84 eV with PBE to 1.05 eV with SCAN, while for ZrIrSb, it increased from 1.41 eV with PBE to 1.71 eV with SCAN. Under the application of strains, both compounds demonstrated an increased band gap under compressive strain, while the application of tensile strain led to a decrease in the band gap, resulting in an indirect-to-direct band gap transition for ZrIrSb. Remarkably, under all strain values, whether tensile or compressive, the SCAN functional consistently exhibited a larger band gap compared to PBE, indicating its accurate description of the material’s electronic structure. The calculated Density of States (DOS) and Partial Density of States (PDOS) reveal that the valence band extremum (VBM) primarily consisted of Ti/Zr-d orbitals, while the conduction band maxima (CBM) predominantly involved strong hybridization between Ti/Zr-d, Ir-d, and Sb-p states. Notably, the SCAN functional predicted higher orbital contributions to Total Density of States (TDOS) compared to the PBE approximation. Importantly, both half-Heusler materials exhibited mechanical and dynamical stability under various strain conditions.

Publisher

IOP Publishing

同舟云学术

1.学者识别学者识别

2.学术分析学术分析

3.人才评估人才评估

"同舟云学术"是以全球学者为主线,采集、加工和组织学术论文而形成的新型学术文献查询和分析系统,可以对全球学者进行文献检索和人才价值评估。用户可以通过关注某些学科领域的顶尖人物而持续追踪该领域的学科进展和研究前沿。经过近期的数据扩容,当前同舟云学术共收录了国内外主流学术期刊6万余种,收集的期刊论文及会议论文总量共计约1.5亿篇,并以每天添加12000余篇中外论文的速度递增。我们也可以为用户提供个性化、定制化的学者数据。欢迎来电咨询!咨询电话:010-8811{复制后删除}0370

www.globalauthorid.com

TOP

Copyright © 2019-2024 北京同舟云网络信息技术有限公司
京公网安备11010802033243号  京ICP备18003416号-3