Tezze Daniel, Pereira José M, Asensio Yaiza, Ipatov Mihail, Calavalle Francesco, Casanova Felix, Bittner Alexander M, Ormaza Maider, Martín-García Beatriz, Hueso Luis E, Gobbi Marco
CIC nanoGUNE BRTA, 20018 San Sebastian, Spain.
SGIker Medidas Magnéticas Gipuzkoa, UPV/EHU, 20018 San Sebastian, Spain.
Nanoscale. 2022 Jan 27;14(4):1165-1173. doi: 10.1039/d1nr07281a.
Atomically thin van der Waals magnetic crystals are characterized by tunable magnetic properties related to their low dimensionality. While electrostatic gating has been used to tailor their magnetic response, chemical approaches like intercalation remain largely unexplored. Here, we demonstrate the manipulation of the magnetism in the van der Waals antiferromagnet NiPS through the intercalation of different organic cations, inserted using an engineered two-step process. First, the electrochemical intercalation of tetrabutylammonium cations (TBA) results in a ferrimagnetic hybrid compound displaying a transition temperature of 78 K, and characterized by a hysteretic behavior with finite remanence and coercivity. Then, TBA cations are replaced by cobaltocenium an ion-exchange process, yielding a ferrimagnetic phase with higher transition temperature (98 K) and higher remanent magnetization. Importantly, we demonstrate that the intercalation and cation exchange processes can be carried out in bulk crystals and few-layer flakes, opening the way to the integration of intercalated magnetic materials in devices.
原子级薄的范德华磁性晶体具有与其低维特性相关的可调磁性能。虽然静电门控已被用于调整其磁响应，但诸如插层等化学方法在很大程度上仍未得到探索。在这里，我们展示了通过插入不同的有机阳离子来操纵范德华反铁磁体NiPS中的磁性，使用一种设计的两步法进行插入。首先，四丁基铵阳离子（TBA）的电化学插层产生一种亚铁磁混合化合物，其转变温度为78 K，具有有限剩磁和矫顽力的磁滞行为。然后，通过离子交换过程，TBA阳离子被钴茂取代，产生具有更高转变温度（98 K）和更高剩余磁化强度的亚铁磁相。重要的是，我们证明插层和阳离子交换过程可以在块状晶体和少层薄片中进行，为将插层磁性材料集成到器件中开辟了道路。
