Room-temperature ferromagnetic properties of Cu-doped ZnO rod arrays

摘要

We have investigated properties of the Cu-doped ZnO crystalline film synthesized by the hydrothermal method. X-ray diffraction and X-ray photoelectron spectroscopy results provide the evidence that Cu~(2+) is incorporated into the ZnO lattices. Photoluminescence spectrum of the rod arrays shows that the UV emission peak shifts a little to lower energy and its intensity decreased. There are another two emission peaks centred in blue and green regions because of the incorporation of Cu~(2+) ions. The rod arrays have exhibited room-temperature ferromagnetic behaviour with the remanence of 0-926 x 10~(-3) emu/cm~3. We suggest that the exchange interaction between local spin-polarized electrons (such as the electrons of Cu~(2+) ions) and conductive electrons is the cause of room-temperature ferromagnetism.