Room-temperature ferromagnetic Mn-doped ZnO nanocrystal synthesized by hydrothermal method under high magnetic field

Mn-doped ZnO nanocrystal have been synthesized by the hydrothermal method under a 4 T pulsed magnetic field. X-ray diffraction (XRD) and scanning electron microscopy (SEM) characterizations reveal the samples are nano-columns with a hexagonal wurtzite ZnO structure. Raman measurement indicates that internal stress and structure defects of the samples increase due to the Mn atoms intercalate into the ZnO crystal lattice. Vibrating sample magnetometer (VSM) detection reveals well room-temperature ferromagnetism for our Mn-doping samples. The origin of room-temperature ferromagnetism may arise from the exchange interaction between Mn2+ ions and defects in ZnO. Combined with XRD, Raman and VSM measurement, it can also find that high pulsed magnetic field introduces more defects into Mn-doped ZnO samples, thus leads to the enhancement of their saturation magnetization.