Room‐temperature ferromagnetism of ZnO/Zn0.96Mn0.04O core‐shell nanowimble

ZnO/Zn 0.96 M n0.04 O core-shell nanowimbles were prepared in two steps: ZnO nanowimbles were synthesized by the standard thermal evaporation method, followed by depositing Zn 0.96 Mn 0.04 O onto the surface of the prepared ZnO nanowimble using an ultrahigh-vacuum radio-frequency magnetron sputtering system. The scanning electron microscopy images show that the morphology, the alignment and the uniformity of ZnO/Zn 0.96 Mn 0.04 O core-shell nanowimbles are maintained as for the as-prepared uncoated ZnO nanowimble, and the thickness of the magnetic Zn 0.96 Mn 0.04 O layer is about 20 nm. The XRD analysis reveals that Mn is incorporated well into the wurtzite ZnO without forming Mn oxide. The magnetic property measurement shows that the ZnO/Zn 0.96 Mn 0.04 O nanowimble is in the ferromagnetic state at room temperature. The coercive field turns out to be as large as 109 Oe and 153 Oe at 300 K and 10 K, respectively.