Spin chiral anisotropy (SChA) refers to the occurrence of different spin polarization in antipodal chiral structures. Herein, we report the SChA in diamagnetic chiral mesostructured In₂O₃ films (CMIFs) with manifestation of chirality-dependent magnetic circular dichroism (MCD) signals. CMIFs were grown on fluorine-doped tin dioxide conductive glass (FTO) substrates synthesized via a hydrothermal route, using malic acid as symmetry-breaking agents. Two levels of chirality have been identified in CMIFs: primary nanoflakes with atomically twisted crystal lattices and secondary helical stacking of the nanoflakes. CMIFs exhibit chirality-dependent asymmetric MCD signals due to the different interaction of chirality-induced effective magnetic field and external magnetic field, which distinguish from the commonly observed external magnetic field-dependent symmetric MCD signals. These findings provide insights into spin manipulation of spin-paired diamagnets.

Hematite (α-Fe₂O₃) is known to undergo conversion from weak ferromagnetic to antiferromagnetic as the temperature decreases below the Morin temperature (T_M = 250 K) due to spin moment rotation occurring during the Morin transition (MT). Herein, we endowed hematite with mesostructured chirality to maintain weak ferromagnetism without MT. Chiral mesostructured hematite (CMH) nanoparticles were prepared by a hydrothermal method with glutamic acid (Glu) as the symmetry-breaking agent. The triangular bipyramidal CMH nanoparticles were composed of helically cleaved nanoflakes with twisted crystal lattice. Field-cooled (FC) magnetization measurements showed that the magnetic moments of CMH were stabilized without MT within the temperature range of 10–300 K. Hysteresis loop measurements confirmed the weak ferromagnetism of CMH. The enhanced Dzyaloshinskii–Moriya interaction (DMI) was speculated to be responsible for the temperature-independent weak ferromagnetism, in which the spin configuration would be confined with canted antiferromagnetic coupling due to the mesostructured chirality of CMH.

The self-assembly of DNA provides an attractive approach to understanding structural formation mechanism in living organisms and to assisting applications in materials chemistry. Herein, we investigated the effect of metal ions on chiral self-assembly of DNA through the synthesis of chiral mesostructured silica via self-assembly of metal ions, DNA, and silica source. 31 types of multivalent cationic metal ions were found to induce formation of chiral impeller-like DNA-silica complexes due to the chiral stacking of DNA. The strength of the interaction between the metal ion and phosphate group of DNA was speculated for the chiral stacking of DNA due to close distance of adjacent DNA to assure mutual recognition. Theoretical calculations indicated that chiral packing of DNA depends on the stability of the bridging phosphate-metal ion-phosphate bonds of DNA based on electron delocalization in d-orbital conjugation of metal ions.