Meanwhile, the C-site ion occupies the tetrahedrally coordinated 24d site, which has a 4 (C4i = S2) site symmetry, centred among four oxygen ions . This specific site occupancy and coordination geometry preserve the highly symmetric cubic structure, which contributes to the distinct physical and optical properties of the materials . The variety of site symmetries raises the opportunity to incorporate various dopants with suitable ionic sizes. The incorporation of indium ions In 3+ on the 16a site into garnet structures can substantially affect the optical properties of the material, primarily by modifying the electronic environment and due to the large ionic radius of In 3+ . The In 3+ ions modify the nature of the chemical bonds in the compound resulting in an expectedly lower band gap compared to classic YAG. Moreover, the garnet crystal structure provides a stable and well-ordered lattice for incorporating luminescent lanthanoid activators on the 24c site, resulting in efficient radiative transitions and high thermal inertness of the luminescence . The high symmetry of the host compound can lead to more efficient radiative transitions and a narrower distribution of energy levels, which is essential for producing sharp and well-defined emission spectra .