A Comparison of the magnetic characteristics and exchange spring effect of Y-substituted Co₂Mn_1-xYxO₄ composite spinel oxides

Magnetic spinel oxides are materials that exhibit unique magnetic properties due to their crystal structure and composition. Herein, we report the sol-gel synthesis of Y-substituted Co2Mn1-xYxO4 (0 <= x <= 0.1) inverse spinel oxides. X-ray diffraction pattern confirms the single-phase cubic structure with space group Fd3m. Magnetic susceptibility measurement results exhibited the para-ferrimagnetic phase transition near T-C = 174 K. Also, another phase transition near a specific temperature T* = 76 K, below T-C of Y-doped samples. Furthermore, the magnetic entropy change analysis also confirmed the magnetic phase transition near the temperature of T*. Moreover, with the phase transition near T*, Y-doped samples show magnetic anomalies at low temperatures. Similarly, the analysis of magnetic entropy change and the magnetic hysteresis loops show the coexistence of "soft " and "hard" ferromagnetic phases at low temperatures in Y-substituent Co2Mn1-xYxO4 samples. Using the coupling of the "soft/hard" ferromagnetic phase boundary, a noticeable exchange spring effect can be observed at low temperatures. Due to the exchange spring effect, the magnetic energy product (BH)(max) up to 3.1 MJ m(-3) can be obtained at 2 K. Such insights can help to optimize the behavior of magnetic materials and structures, leading to improved performance and functionality in applications such as magnetic data storage, magnetic sensors, spintronics, and magnetic nanoparticles.