Partially decoupled tuning of the electronic and magnetic properties via spin-chain compounds for spintronics: A first principles study

Independent control of electronic and magnetic properties is highly desirable for spintronics and magnetic semiconductors. Using first-principles calculations, we demonstrate that the partially decoupled control of properties can be achieved in the spin-chain compound Ba₁₂Cr₄S₂₀, which contains spatially separated magnetic and non-magnetic chains. The magnetic chains are composed of Cr-centred octahedra surrounded by S atoms, whereas the non-magnetic chains consist solely of S atoms. We show that the electronic and magnetic properties can be partially decoupled through selective chemical substitution in these distinct chains. Substituting S with P in the non-magnetic chains induces a conducting state while preserving the magnetic ground state, thereby selectively modifying the electronic properties. In contrast, substituting Cr with Co changes the magnetic ground state from antiferromagnetic to ferromagnetic without significantly affecting the electronic structure, while Ni substitution leads to weak ferrimagnetism. By comparison, Ti substitution simultaneously closes the band gap and stabilises a ferromagnetic ground state, affecting both the electronic and magnetic properties. These findings establish spin-chain compounds as a promising platform for the independent engineering of electronic and magnetic functionalities, opening new opportunities for spin-chain-based spintronic materials.