Thin film fabrication of 2D layered organic–inorganic hybrid perovskites (2D‐OIHPs) for spintronic applications has been attempted using solution‐based process like Langmuir–Blodgett technique. However, monolayer or few‐layered 2D magnets are not yet realized, even though a wide spectrum of 2D Ruddlesden–Popper (RP) OIHPs are known as quasi‐2D Heisenberg magnets in bulk compounds. Here, chemical exfoliation by solvent engineering is applied to successfully synthesize large‐sized, few unit‐cell‐thick 2D RP‐OIHPs. Comprehensive structural characterization reveals that binary co‐solvents with high relative polarity in spin coating technique are the most effective among nine kinds of solvents. Above all, this enables few‐layered 2D RP‐OIHP ultrathin films sustaining their intrinsic magnetic order. It is found that XY‐like magnetic anisotropy driven by Jahn–Teller effect responsible for ferromagnetism in seven‐layered (C₆H₅CH₂CH₂NH₃)₂CuCl₄ ultrathin films remains very robust, whereas Ising‐like dipolar anisotropy responsible for canted antiferromagnetism in ten‐layered (C₆H₅CH₂CH₂NH₃)₂MnCl₄ ultrathin films is greatly reduced. It is expected that ferromagnetism even at monolayer limit should be possible by means of further sophisticated solvent engineering as long as Jahn–Teller effect is active. The chemical exfoliation using solvent engineering unambiguously can bring about a new breakthrough in the development of 2D RP‐OIHP van der Waals magnets for ultrahigh energy‐efficient spintronic, opto‐spintronic devices.

中文翻译：

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化学剥落的二维Ruddlesden-Pop有机-无机卤化物钙钛矿超薄膜的固有磁阶。

已经尝试使用基于溶液的工艺（例如Langmuir-Blodgett技术）来制造用于自旋电子学的2D层有机-无机杂化钙钛矿（2D-OIHPs）薄膜。但是，即使将大范围的2D Ruddlesden-Popper（RP）OIHP称为散装化合物的准2D Heisenberg磁体，也尚未实现单层或几层的2D磁体。在这里，通过溶剂工程进行的化学剥离技术成功地合成了大尺寸，很少单位单元厚度的二维RP-OIHP。全面的结构表征表明，旋涂技术中具有较高相对极性的二元助溶剂是九种溶剂中最有效的。最重要的是，这使几层2D RP-OIHP超薄膜能够保持其固有的磁序。₆ H ₅ CH ₂ CH ₂ NH ₃）₂ CuCl ₄超薄膜仍然非常坚固，而类似Ising的偶极各向异性导致十层（C ₆ H ₅ CH ₂ CH ₂ NH ₃）₂ MnCl ₄倾斜的反铁磁性。超薄膜大大减少了。可以预期，只要Jahn–Teller效应有效，就可以通过进一步复杂的溶剂工程来实现甚至在单层极限条件下的铁磁性。明确地使用溶剂工程进行化学剥离可以为超高能效自旋电子，光电自旋电子器件的2D RP-OIHP van der Waals磁体的开发带来新的突破。