An Ideal Spin Filter: Long-Range, High-Spin Selectivity in Chiral Helicoidal 3‑Dimensional Metal Organic Frameworks

• Published in: Nano letters Vol. 20; no. 12; pp. 8476 - 8482
• Main Authors: Huizi-Rayo, Uxua, Gutierrez, Junkal, Seco, Jose Manuel, Mujica, Vladimiro, Diez-Perez, Ismael, Ugalde, Jesus M, Tercjak, Agnieszka, Cepeda, Javier, San Sebastian, Eider
• Format: Journal Article
• Language: English
• Published: American Chemical Society 09.12.2020
• Subjects: CISS effect; Tartrate; 3D; Metal−Organic Frameworks; Chirality; AFM; Spin polarization; Dy(III); Spintronic; Helicity
• ISSN: 1530-6984; 1530-6992
• DOI: 10.1021/acs.nanolett.0c02349

An enantiopure, conductive, and paramagnetic crystalline 3-D metal–organic framework (MOF), based on Dy­(III) and the l-tartrate chiral ligand, is proved to behave as an almost ideal electron spin filtering material at room temperature, transmitting one spin component only, leading to a spin polarization (SP) power close to 100% in the ±2 V range, which is conserved over a long spatial range, larger than 1 μm in some cases. This impressive spin polarization capacity of this class of nanostructured materials is measured by means of magnetically polarized conductive atomic force microscopy and is attributed to the Chirality-Induced Spin Selectivity (CISS) effect of the material arising from a multidimensional helicity pattern, the inherited chirality of the organic motive, and the enhancing influence of Dy­(III) ions on the CISS effect, with large spin–orbit coupling values. Our results represent the first example of a MOF-based and CISS-effect-mediated spin filtering material that shows a nearly perfect SP. These striking results obtained with our robust and easy-to-synthesize chiral MOFs constitute an important step forward in to improve the performance of spin filtering materials for spintronic device fabrication.