Cation site preference in YIG: correlation with magnetic and optical properties

The occupancy of cations at the octahedral and tetrahedral sites of yttrium iron garnet (YIG) is critical for determining its optical and magnetic characteristics, which are essential for a range of advanced technological applications, including magneto-optical devices, spintronics, and photonics. The substitution of various cations alters the crystal structure and interaction dynamics within the lattice, thereby influencing the magnetic anisotropy, Faraday rotation, and optical absorption of the material. In particular, the tetrahedral and octahedral sublattices, predominantly occupied by Fe3+ ions, serve as key doping sites, with each site affecting distinct aspects of the material's behavior. Doping in the tetrahedral sublattice modifies exchange interactions, thereby affecting spin-wave dynamics and magnetic anisotropy, while doping in the octahedral sublattice influences electron density, spin alignment, and local crystal-field interactions, resulting in changes to magnetic saturation, coercivity, and optical properties. These modifications also induce lattice strain and structural distortions, which are crucial for optimizing YIG performance. This review presents a comprehensive analysis of how cation doping at these sites modulates the material's properties, offering valuable insights into the design of YIG-based materials for next-generation optoelectronic and magneto-optical devices. The article focuses recent findings to underscore the potential of targeted cation occupancy strategies in tailoring YIG properties for emerging technological advancements.