Figure 4
From: Ultraviolet Laser Action in Ferromagnetic Zn1−x Fe x O Nanoneedles
a XPS spectra of Zn0.989Fe0.011O NDs, the insert shows the Fe 2p XPS core-level spectra; O 1s XPS core-level spectra of b undoped ZnO NDs, c Zn0.989Fe0.011O NDs, and d Zn0.983Fe0.017O NDs