The rare-earth-free ferrimagnet Mn₄N has attractive features for spintronics applications, because it possesses a perpendicular magnetization, due to a relatively large magnetic anisotropy constant of ∼10⁵ J m⁻³ and a small spontaneous magnetization of ∼100 kA m⁻¹, and a large spin polarization (P = 0.8). More crucially, it is possible to reach the magnetic compensation at room temperature, by tuning its constituent elements in compounds such as Mn_4−xNi_xN and Mn_4−xCo_xN. This is particularly interesting for spin-torque-based spintronics applications, because at the vicinity of the magnetization and/or angular momentum compensation points, the switching currents can be reduced significantly, thereby leading to lower switching energies and higher switching speed. In this review article, we emphasize the importance of epitaxial growth of Mn₄N films by comparing the results obtained on two different substrates, MgO(001) and SrTiO₃(001). We then present the achievement of ultrafast current-induced domain wall motion (CIDWM) in Mn₄N microstrips, and study the magnetic compensations in Mn_4−xNi_xN and Mn_4−xCo_xN at room temperature, proved by x-ray magnetic circular dichroism measurements. Finally, we offer future prospects for such Mn₄N-based compensated ferrimagnets.

中文翻译：

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稀土自由铁氧体Mn4N的现状及Mn4N基补偿铁氧体的未来前景

无稀土铁氧体Mn ₄ N具有自旋电子学的诱人特性，因为它具有约^{10 5} J m ^-3的相对较大的磁各向异性常数和约100 kA m的自发性磁化强度，因此具有垂直磁化强度^-1和大的自旋极化（P = 0.8）。更关键的是，通过调节其在诸如Mn _{4- x} Ni _x N和Mn _{4- x} Co _x等化合物中的组成元素，可以在室温下达到磁补偿。N.这对于基于自旋转矩的自旋电子学应用特别有趣，因为在磁化和/或角动量补偿点附近，开关电流可以显着降低，从而导致较低的开关能量和较高的开关速度。在这篇综述文章中，我们通过比较在两种不同的衬底MgO（001）和SrTiO ₃（001）上获得的结果来强调外延生长Mn ₄ N薄膜的重要性。然后，我们介绍了在Mn ₄ N微带中超快电流引起的畴壁运动（CIDWM）的实现，并研究了Mn _{4− x} Ni _x N和Mn _{4− x} Co _x中的磁补偿N在室温下通过X射线磁性圆二色性测量得到证明。最后，我们提供了这种基于Mn ₄ N的补偿铁氧体的未来前景。