The structural, magnetic, and dielectric properties of Cr-substituted samarium iron garnet \((S{m}_{3}\:F{e}_{5-x}\:C{r}_{x}\:{O}_{12},\:x\:=\:0.0-0.5)\) were systematically investigated to understand the impact of Cr incorporation on the garnet framework. X-ray diffraction analysis confirmed single-phase cubic garnet formation, accompanied by a gradual reduction in lattice parameter and grain size with increasing Cr content. Magnetic measurements revealed two characteristic spin-reorientation transitions in the parent compound, both of which became progressively suppressed upon Cr substitution due to the weakening of \(Fe\left(a\right)-O-Fe\left(d\right)\) superexchange interactions. A consistent decrease in magnetization was observed as magnetic \(Fe^{3+}\) ions were replaced by lower-moment \(Cr^{3+}\) ions. Impedance spectroscopy demonstrated clear dielectric relaxation behavior, with relaxation peaks shifting toward higher frequencies for Cr-doped samples that indicates reduced relaxation time and enhanced charge transport. Overall, Cr substitution effectively tunes the magnetic ordering, microstructure, and dielectric response of SmIG, highlighting its potential for multifunctional magneto-dielectric and high-frequency device applications.
