AI 中文总结
本研究优化了溅射法生长Mn4N薄膜的条件，明确衬底对其结构与磁性的影响，揭示外延应变及界面效应对垂直磁各向异性的作用，证实其可实现高效电流诱导磁化翻转，为自旋电子器件提供了优质无稀土材料平台。
AI 中文摘要
亚铁磁Mn4N因低磁化强度、高畴壁迁移率和强反常霍尔响应，近来成为自旋电子器件领域极具潜力的无稀土材料平台。然而，通过可扩展沉积技术制备兼具垂直磁各向异性（PMA）和自旋轨道转矩（SOT）功能的薄膜仍是重大挑战。本研究系统探究了反应磁控溅射法生长Mn4N薄膜的过程，确定了适用于SOT应用的高质量薄膜所需条件。研究表明，在MgO(100)衬底上可获得具有强PMA的外延单晶Mn4N薄膜，而在SrTiO3(100)衬底上沉积的薄膜则呈现织构结构。优化后的薄膜显示出方形磁滞回线，具备高剩磁、大且可调的矫顽力以及显著的反常霍尔效应。结合结构、磁性与磁输运表征及密度泛函理论计算，研究揭示外延应变在调控磁各向异性中起关键作用，但并非唯一影响因素，同时强调界面效应对稳定PMA的重要性。最终，在Mn4N/Pt双层膜中实现了高效的电流诱导磁化翻转，证实了其强界面自旋透明性。这些发现确立了溅射法制备的Mn4N作为高效能自旋轨道电子器件的极具潜力且多功能的材料平台。
英文摘要
Ferrimagnetic Mn4N has recently emerged as a promising rare-earth-free platform for spintronic devices due to its low magnetization, high domain wall mobility, and strong anomalous Hall response. However, the realization of thin films with robust perpendicular magnetic anisotropy (PMA) and spin-orbit torque (SOT) functionality through scalable deposition techniques remains a significant challenge. In this work, we systematically investigate the growth of Mn4N thin films by reactive magnetron sputtering and determine the conditions required to achieve high-quality films suitable for SOT applications. We demonstrate that epitaxial, single-crystalline Mn4N films with strong PMA can be obtained on MgO(100), whereas films deposited on SrTiO3(100) exhibit a textured structure. The optimized films show square-shaped hysteresis loops with high remanence, large and tunable coercivity, and a pronounced anomalous Hall effect. By combining structural, magnetic, and magnetotransport characterization with density functional theory calculations, we reveal that epitaxial strain plays a key role in tuning magnetic anisotropy, while also showing that it is not the only contributing factor. In particular, our results emphasize the importance of interfacial effects in stabilizing PMA. Finally, we demonstrate efficient current-induced magnetization switching in Mn4N/Pt bilayers, confirming strong interfacial spin transparency. These findings establish sputtered Mn4N as a promising and versatile material platform for energy-efficient spin-orbitronic devices.
