Chiral Mesostructured NiO Films with Spin Polarisation

Te Bai; Jing Ai; Liyang Liao; Junwei Luo; Cheng Song; Yingying Duan; Lu Han; Shunai Che

doi:10.1002/anie.202101069

Chiral Mesostructured NiO Films with Spin Polarisation

Angew Chem Int Ed Engl. 2021 Apr 19;60(17):9421-9426. doi: 10.1002/anie.202101069. Epub 2021 Mar 16.

Authors

Te Bai¹, Jing Ai², Liyang Liao³, Junwei Luo⁴, Cheng Song³, Yingying Duan², Lu Han², Shunai Che^{1

2}

Affiliations

¹ School of Chemistry and Chemical Engineering, State Key Laboratory of Metal Matrix Composites, Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, P.R. China.
² School of Chemical Science and Engineering, Tongji University, 1239 Siping Road, Shanghai, 200092, P. R. China.
³ Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing, 100084, P. R. China.
⁴ State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, 100083, P.R. China.

PMID: 33554464
DOI: 10.1002/anie.202101069

Abstract

Spin polarisation is found in the centrosymmetric nonferromagnetic crystals, chiral mesostructured NiO films (CMNFs), fabricated through the symmetry-breaking effect of a chiral molecule. Two levels of chirality were identified: primary nanoflakes with atomically twisted crystal lattices and secondary helical stacking of the nanoflakes. Spin polarisation of the CMNFs was confirmed by chirality-dependent magnetic-tip conducting atomic force microscopy (mc-AFM) and magnetic field-independent magnetic circular dichroism (MCD). Electron transfer in the symmetry-breaking electric field was speculated to create chirality-dependent effective magnetic fields. The asymmetric spin-orbit coupling (SOC) generated by effective magnetic fields selectively modifies the opposite spin motion in the antipodal CMNFs. Our findings provide fundamental insights for directional spin control in unprecedented functional inorganic materials.

Keywords: antiferromagnetic material; chiral mesostructure; chirality-dependent spin polarisation; magnetic circular dichroism; magnetic-tip conducting atomic force microscopy.

Abstract

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