Synthesis and magnetic properties of Mn-doped ZnO hollow nanospheres

A facile approach to fabricate Mn-doped ZnO hollow nanospheres is reported. Zn2+ and Mn2+ cations were adsorbed onto the surface of carbon template to form a core/shell structure in solution. Subsequent calcination of the core/shell structure would lead to the formation of Mn-doped ZnO hollow nanospheres. The magnetic properties of the hollow spheres were dependent on the calcination temperature. The room-temperature ferromagnetism was obtained when the temperature was less than 900 °C. However, the ferromagnetic behavior disappeared when the temperature was elevated to 1200 °C. The possible reason is the short-ranged ferromagnetic spin–spin interaction between neighboring Mn atoms by forming a bridge bond by Hi.