Structure and magnetism of mixed-valent iron oxysulfides Sr3Fe4O6S2 (Sr3(Fe3+)2O5(Fe2+)2OS2) and Sr4Fe4O7S2 (Sr4(Fe3+)2O6(Fe2+)2OS2)

Abstract

The crystal and magnetic structures of Sr₃Fe₄O₆S₂ (Sr₃Fe₂O₅Fe₂OS₂) and Sr₄Fe₄O₇S₂ (Sr₄Fe₂O₆Fe₂OS₂), designed using a building-block approach, are reported. They are fully charge-ordered with Fe²⁺ and Fe³⁺ ions in distinct layers showing independent long-range magnetic order. Complex microstructures in some regions suggest new targets.