Sofi Mudasir Younis, Gupta Dinesh C
Department of Physics, Jamia Millia Islamia, New Delhi, 110025, India.
Condensed Matter Theory Group, School of Studies in Physics, Jiwaji University, Gwalior, 474011, India.
Sci Rep. 2022 Nov 14;12(1):19476. doi: 10.1038/s41598-022-22633-y.
In the hunt for novel materials, we present self-consistent ab initio simulations of the structural stability, electronic profile, and transport properties of f-electron-based RbMO (M = Np, Pu) perovskites within the context of density functional theory. The structural stability and thermodynamic concerns are fixed by relaxing the crystal structure and computing the energy of formation, respectively. Furthermore, the decisive physical features of given materials have been outlined using the optimised lattice constant retrieved from structural optimizations. The ground state magnetic phase stability is ascertained by minimizing Birch Murnaghan's equation of state in distinct magnetic phases, upholding the ferromagnetic phase (FM) as the ground state magnetic phase, which is further backed by positive Curie Wiess constant values. To specify the electronic structure, a mix of the two approximations GGA and GGA + mBJ has been executed, both of which assert the half-metallic character, culminating in 100% spin polarisation at the Fermi level. The study of the magnetic moment and Curie temperature of each material has further been assessed in the present study. Apart from half-metallicity, the thermoelectric response of the present materials is quantified by exploring the chemical potential dependency of several transport parameters like Seebeck coefficient, electrical and thermal conductivity, power factor, etc. Moreover, the thermoelectric competence has been tested using a zT calculation, adapting values of 1.01 and 0.987 at 300 K for RbNpO and RbPuO, respectively. The high electronic zT at encompassing temperatures uncovers the significant utility of these materials in both low-and high-temperature thermoelectric device applications. In essence, the comprehensive survey of these alloys could certainly open up their possibilities in spintronics, thermoelectric, and solid-state (RTG) device applications.
在寻找新型材料的过程中，我们在密度泛函理论的背景下，对基于f电子的RbMO（M = Np，Pu）钙钛矿的结构稳定性、电子分布和输运性质进行了自洽的从头算模拟。结构稳定性和热力学问题分别通过松弛晶体结构和计算形成能来确定。此外，利用从结构优化中获得的优化晶格常数概述了给定材料的决定性物理特征。通过在不同磁相中最小化Birch Murnaghan状态方程来确定基态磁相稳定性，支持铁磁相（FM）作为基态磁相，这进一步得到正居里-外斯常数的支持。为了确定电子结构，执行了GGA和GGA + mBJ这两种近似方法的组合，两者都表明具有半金属特性，在费米能级处达到100%的自旋极化。本研究还进一步评估了每种材料的磁矩和居里温度。除了半金属性之外，通过探索几个输运参数（如塞贝克系数、电导率和热导率、功率因数等）的化学势依赖性来量化本材料的热电响应。此外，通过zT计算测试了热电性能，RbNpO和RbPuO在300 K时的zT值分别为1.01和0.987。在环境温度下的高电子zT值揭示了这些材料在低温和高温热电装置应用中的重要用途。本质上对这些合金的全面研究肯定会为它们在自旋电子学、热电和固态（RTG）装置应用中开辟可能性。
