Tunable magnetization steps in mixed valent ferromagnet Eu(2)CoMnO(6)

Magnetic properties can be manipulated to enhance certain functionalities by tuning different material processing parameters. Here, we present the controllable magnetization steps of hysteresis loops in double-perovskite single crystals of Eu(2)CoMnO(6). Ferromagnetic order emerges below T(C) ≈ 122 K along the crystallographic c axis. The difficulty in altering Co(2+) and Mn(4+) ions naturally induces additional antiferromagnetic clusters in this system. Annealing the crystals in different gas environments modifies the mixed magnetic state, and results in the retardation (after O(2)-annealing) and bifurcation (after Ar-annealing) of the magnetization steps of isothermal magnetization. This remarkable variation offers an efficient approach for improving the magnetic properties of double-perovskite oxides.