Faiza-Rubab S, Naseem Shahnila, Alay-E-Abbas Syed Muhammad, Zulfiqar M, Zhao Y, Nazir S
Department of Physics, University of Sargodha, Sargodha, 40100, Pakistan.
Applied Physics, Division of Materials Science, Department of Engineering Sciences and Mathematics, Luleå University of Technology, 97187 Luleå, Sweden.
Phys Chem Chem Phys. 2021 Sep 15;23(35):19472-19481. doi: 10.1039/d1cp03247j.
Half-metallic ferromagnetic materials have attracted a lot of attention due to their probable technological applications in spintronics. In this respect, doping plays a crucial role in tailoring or controlling the physical properties of the system. Herein, the impact of both hole and electron doping on the structural, electronic and magnetic properties of the recent high pressure synthesized non-magnetic insulator BaCaMoO double perovskite oxide are investigated by replacing one of the Mo ions with Nb and Tc. The structural and mechanical stability of the undoped/doped materials are analyzed by calculating the formation energies and stiffness tensors, respectively, which confirm the system's stability. Interestingly, our results revealed that Nb- and Tc-doped systems display an electronic transition from insulating to p- and n-type half-metallic ferromagnetic states, respectively. The most striking feature of the present study is that oxygen ions become spin-polarized, with a magnetic moment of ∼0.12 per atom, and are mainly responsible for conductivity in the Nb-doped system. However, the admixture of Tc 4d non-degenerate orbitals are primarily contributing to the metallicity in the Tc-doped structure, with a moment of ∼0.59 . It is also found that Nb and Tc ions remain in the 5+ and 7+ states with electronic configurations of t22g↑t22g↓e0g↑e0g↓ and t32g↑t22g↓e0g↑e0g↓, with spin states of = 0 and = 1/2 in the individual doped systems, respectively. Hence, the present work proposes that a doping strategy with a suitable candidate could be beneficial to tune the physical properties of the materials for their potential utilization in advanced spin-based devices.
半金属铁磁材料因其在自旋电子学中可能的技术应用而备受关注。在这方面，掺杂在调整或控制体系的物理性质中起着关键作用。在此，通过用铌（Nb）和锝（Tc）取代其中一个钼（Mo）离子，研究了空穴和电子掺杂对最近高压合成的非磁性绝缘体BaCaMoO双钙钛矿氧化物的结构、电子和磁性性质的影响。分别通过计算形成能和刚度张量来分析未掺杂/掺杂材料的结构和力学稳定性，这证实了体系的稳定性。有趣的是，我们的结果表明，Nb掺杂和Tc掺杂体系分别显示出从绝缘态到p型和n型半金属铁磁态的电子转变。本研究最显著的特征是，氧离子变得自旋极化，每个原子的磁矩约为0.12，并且在Nb掺杂体系中主要负责导电性。然而，Tc的4d非简并轨道的混合主要促成了Tc掺杂结构中的金属性，磁矩约为0.59。还发现，在各自的掺杂体系中，Nb和Tc离子分别保持5 +和7 +价态，电子构型分别为t22g↑t22g↓e0g↑e0g↓和t32g↑t22g↓e0g↑e0g↓，自旋态分别为S = 0和S = 1/2。因此，本工作提出，采用合适的候选物进行掺杂策略可能有利于调整材料的物理性质，以用于先进的自旋基器件中的潜在应用。
