Elaggoune Warda, Abdullahi Yusuf Zuntu, Ahmad Sohail, Thong Leng Lim
Laboratoire de Physique des Matériaux (L2PM), Faculté des Mathématiques, de l'informatique et des Sciences de la Matière, Université 8 Mai 1945 BP 401 Guelma Algeria
Department of Physics, Aydin Adnan Menderes University Aydin 09010 Turkey.
RSC Adv. 2025 Aug 1;15(33):27403-27414. doi: 10.1039/d5ra03942h. eCollection 2025 Jul 25.
The recent synthesis of two-dimensional (2D) MoSiN and WSiN crystals has given rise to a new class of 2D materials with distinctive properties and significant potential for advanced technologies. The transition metal (TM) elements can potentially be substituted with other elements from the periodic table, enabling the introduction of new members into this emerging 2D family. Building on this framework, we propose a new family of light-element-based 2D ternary compounds of MgZN (Z = Si, Ge) and their Janus derivative MgGeSiN using first-principles density functional theory (DFT) calculations. All three monolayers are found to be dynamically, thermally, and mechanically stable. MgGeN exhibits a metallic antiferromagnetic (AFM) ground state within the PBE functional, while more accurate HSE-level calculations reveal a weak ferrimagnetic (FiM) configuration. Conversely, MgSiN is a robust half-metallic ferromagnet with 100% spin polarization and a sizable magnetic moment of 5.62 per unit cell. Janus MgGeSiN shows FiM metallic behavior, driven by structural asymmetry. All systems favor an in-plane easy axis magnetization, and our analysis shows that their magnetic behavior follows a unique low-temperature Berezinskii-Kosterlitz-Thouless (BKT) transition, characteristic of the 2D XY-like model. The estimated BKT transition temperatures for MgGeN, MgSiN, and MgGeSiN are approximately 19 K, 4 K, and 16 K, respectively. This study presents the first report of intrinsic FM, AFM, and FiM in this monolayer family, highlighting their potential for advanced low-temperature magnetic device applications.
二维（2D）MoSiN和WSiN晶体的近期合成产生了一类具有独特性质且在先进技术方面具有巨大潜力的新型二维材料。过渡金属（TM）元素有可能被元素周期表中的其他元素取代，从而能够将新成员引入这个新兴的二维材料家族。基于这一框架，我们使用第一性原理密度泛函理论（DFT）计算，提出了一个基于轻元素的MgZN（Z = Si，Ge）二维三元化合物及其Janus衍生物MgGeSiN的新家族。发现所有这三种单层在动力学、热学和力学上都是稳定的。在PBE泛函内，MgGeN表现出金属反铁磁（AFM）基态，而更精确的HSE水平计算揭示了一种弱铁磁（FiM）构型。相反，MgSiN是一种稳健的半金属铁磁体，具有100%的自旋极化和每单位晶胞5.62的可观磁矩。Janus MgGeSiN由于结构不对称而表现出FiM金属行为。所有体系都倾向于面内易轴磁化，并且我们的分析表明它们的磁行为遵循独特的低温贝雷津斯基 - 科斯特利茨 - Thouless（BKT）转变，这是二维XY类模型的特征。MgGeN、MgSiN和MgGeSiN的估计BKT转变温度分别约为19 K、4 K和16 K。这项研究首次报道了这个单层材料家族中的本征铁磁（FM）、反铁磁（AFM）和铁磁（FiM）特性，突出了它们在先进低温磁器件应用中的潜力。
