de Rojas Julius, Quintana Alberto, Lopeandía Aitor, Salguero Joaquín, Muñiz Beatriz, Ibrahim Fatima, Chshiev Mairbek, Nicolenco Aliona, Liedke Maciej O, Butterling Maik, Wagner Andreas, Sireus Veronica, Abad Llibertat, Jensen Christopher J, Liu Kai, Nogués Josep, Costa-Krämer José L, Menéndez Enric, Sort Jordi
Departament de Física, Universitat Autònoma de Barcelona, 08193, Cerdanyola del Vallès, Spain.
Department of Physics, Georgetown University, Washington, DC, 20057, USA.
Nat Commun. 2020 Nov 18;11(1):5871. doi: 10.1038/s41467-020-19758-x.
Magneto-ionics, understood as voltage-driven ion transport in magnetic materials, has largely relied on controlled migration of oxygen ions. Here, we demonstrate room-temperature voltage-driven nitrogen transport (i.e., nitrogen magneto-ionics) by electrolyte-gating of a CoN film. Nitrogen magneto-ionics in CoN is compared to oxygen magneto-ionics in CoO. Both materials are nanocrystalline (face-centered cubic structure) and show reversible voltage-driven ON-OFF ferromagnetism. In contrast to oxygen, nitrogen transport occurs uniformly creating a plane-wave-like migration front, without assistance of diffusion channels. Remarkably, nitrogen magneto-ionics requires lower threshold voltages and exhibits enhanced rates and cyclability. This is due to the lower activation energy for ion diffusion and the lower electronegativity of nitrogen compared to oxygen. These results may open new avenues in applications such as brain-inspired computing or iontronics in general.
磁离子学，即磁性材料中电压驱动的离子传输，很大程度上依赖于氧离子的可控迁移。在此，我们通过对CoN薄膜进行电解质门控，展示了室温下电压驱动的氮传输（即氮磁离子学）。将CoN中的氮磁离子学与CoO中的氧磁离子学进行了比较。这两种材料都是纳米晶体（面心立方结构），并表现出可逆的电压驱动开-关铁磁性。与氧不同，氮传输均匀发生，形成类似平面波的迁移前沿，无需扩散通道的辅助。值得注意的是，氮磁离子学需要较低的阈值电压，并表现出更高的速率和循环性。这是由于与氧相比，离子扩散的活化能较低以及氮的电负性较低。这些结果可能会为诸如受大脑启发的计算或一般的离子电子学等应用开辟新途径。
