Tuning of the spin reorientation and spin switching in Sm-doped NdFeO₃

The tuning of magnetic transitions in rare-earth orthoferrites is critical for developing advanced functional materials. Here, we report on the evolution of spin reorientation (SRT) and spin switching (SSW) in single crystals of Nd_1-xSm_xFeO₃ (x = 0.1, 0.3, and 0.5), grown using an optical floating zone furnace. Structural analysis confirms a systematic lattice contraction within the orthorhombic Pbnm space group upon Sm³⁺ doping. This compositional engineering provides precise control over the SRT, systematically increasing its temperature while narrowing the Γ₂₄ coexistence region. The crystals exhibit type-I spin switching, and most significantly, we demonstrate a unique way of controlling the switching temperature (T_SSW). By employing a negative field-cooling protocol, an exceptionally large tunable range of nearly 158 K was achieved with a minimal cooling field of -20 Oe, the largest reported so far for this material class. These findings establish that doping in orthoferrites is a powerful strategy to create materials with tailored magnetic functionalities for advanced applications.