Room temperature ferromagnetism and optical property of Zn1−xCoxS nanorods

• The maximum concentration of Co2+ ions in the ZnS nanorods is 4.69%.
• The Co2+ ions act as the nonradiative center for the ZnS:Co2+ nanorods.
• We observe the room temperature ferromagnetism for the ZnS:Co2+ nanorods.

In this paper, ZnS:Co2+ nanorods (NRs) have been synthesized by a simple hydrothermal method with ethylenediamine as the oriented-assembly agent at 180 °C. The results showed that the Co2+ ions substituted for the Zn2+ sites in the host ZnS, and the maximum concentration of the Co2+ ions in the ZnS NRs was 4.69%. No Co-related emission peak can be observed and the emission intensity of the ZnS:Co2+ NRs was decreased, indicating that the Co2+ ions only acted as the nonradiative center. The Zn1−xCoxS NRs showed the room temperature ferromagnetism property, and the magnetic saturation (Ms) value was increased as the Co2+ doped ratio increased.