Intrinsic ferromagnetic properties in Cr-doped ZnO diluted magnetic semiconductors

The Cr-doped zinc oxide (Zn1−xCrxO, 0≤x≤0.08) diluted magnetic semiconductors have been synthesized successfully by the sol–gel method. Investigations on magnetic, optical and structural properties of the produced samples have been done. Energy dispersive spectroscopy (EDS) shows the existence of Cr ion in the Cr-doped ZnO. The results of X-ray diffraction (XRD), the transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS) and X-ray absorption fine structure (XAFS) indicate that the Cr ions are at least partially substitutionally incorporated into the crystal lattice of ZnO. The produced samples show good high-Tc (Curie temperature) ferromagnetism (FM) in Cr-doped ZnO nanoparticles with Cr concentration of less than 5 at%. The results of photoluminescence (PL) further testify that FM is an intrinsic property of the Cr-doped ZnO nanoparticles. And the occurrence of FM should mainly contribute to the Cr doping.

Graphical AbstractAs can be seen from the magnetic hysteresis loops of Zn1−xCrxO (x=0.01, 0.03, 0.05, and 0.08) at room temperature under 10 KOe, the samples show good high-Tc ferromagnetism with Cr concentration of less than 5 at%.Figure optionsDownload as PowerPoint slideHighlights
► Zn1−xCrxO(0≤x≤0.08) nanoparticles are successfully synthesized by sol–gel method.
► The Cr ions are substitutionally incorporated into the crystal lattice of ZnO.
► The Cr-doped ZnO nanoparticles show good high-Tc ferromagnetism.
► The ferromagnetism is an intrinsic property of the Cr-doped ZnO nanoparticles.