Magnetic Properties of Low-Dimensional α and γ CoV2O6

In this work, we analyze the magnetic properties of the low-dimensional CoV2O6 powders showing monoclinic (α) and triclinic (γ) crystalline structures. The two phases are constituted of parallel 1D Co chains organized in planes that are separated by vanadium oxide thin layers. Both α and γ phases are antiferromagnetic in the ground state with Neel temperatures of 15 and 7 K, respectively. The magnetization curves recorded at 5 (α phase) and 1.8 K (γ phase) show a stepped variation with sharp field-induced magnetic transitions and a magnetization plateau at one-third of the saturation magnetization. In α-CoV2O6, additional steps are evidenced when the temperature decreased from 5 to 1.8 K. This is accompanied by an increasing hysteresis corresponding to the magnetic field transitions. From the magnetization curves recorded at different temperatures, a magnetic phase diagram could be determined. The estimated Co moment is large and reaches in the α and γ phases 4.5 and 3 μB, respectively, suggesting the exi...