A Comparative Study on the Substitution of Nonmagnetic Ion T3+ (T = Al, Sc and Y; 0 ≤ × ≤ 0.2) on the Co2Sn1−xTxO4 Spinel Oxides to Investigate the Magnetic Characteristics

Co₂Sn_1−xT_xO₄ (T = Al, Sc, and Y; 0 ≤ x ≤ 0.2) magnetic spinel oxides have been synthesized through solid-state reaction. The XRD pattern displays a single-phase cubic structure with space group Fd3m. Moreover, magnetic susceptibility results show that substituting trivalent non-magnetic ions improves the para-ferrimagnetic transition temperature, T_C. Magnetic susceptibility results of direct current (dc) and alternating current (ac) showed that the T³⁺ substitution increased the freezing temperature of the spin-glass state, and was also beneficial to the growth of the spin-glass phase. The apparent magnetic exchange bias effect at low temperatures (T < 20 K) was realized in the Co₂Sn_1−xT_xO₄ samples using the pinning effect in the spin-glass phase. Due to the magnetic exchange bias effect, the magnetism of the system dramatically increased at low temperatures. Thermal exchange bias results show that the coercivity field (H_C) at 10 K increased from 0 for x = 0 samples to ~ 2.1, 1.3, and 2.9 kOe for Al-, Sc-, and Y-doped samples, respectively. It can optimize magnetic materials and architectures, improving performance and practicality in magnetic data storage, magnetic sensors, spintronics, and magnetic nanoparticles.