Study Of The DMS Magnetism Of Doped ZnO

In this paper, the TM_xZn_1-xO Crystals were synthesized by hydrothermal method with mineralizer of 3mol·L^-1KOH, the fill factor of 35%, reaction temperature of 430°C, and time of 24 hours(TM=Mn, Co , Ni, Fe, Sn).The doped chemical element concentration in crystal was determined by electron probe. The atomic percentage of doped chemical element in crystal increased as the concentration of doped chemical element in precursor increased, and it has an extremum. The maximum of the Mn concentration in crystal is above 8at%, the maximum of the Co concentration in crystal is above 5 at%, the maximum of the Fe concentration in crystal is above 0.5at%, the maximum of the Ni concentration in crystal is above 0.65at%. The morphology of the crystal varied with the concentration of doped chemical element in precursor increased. But they all show the hexagonal feature of ZnO wurtzites.The magnetic properties of the TM_xZn_1-xO Crystals were investigated using a SQUID magnetometer. The Zn_1-xMn_xO crystals do not show room-temperature ferromagnetism, presenting antiferromagnetism and high-temperature paramagnetism. The Zn_1-xCo_xO crystal's magnetization vary unobviously as the temperature rises under the room temperature, the hysteresis loop of Zn_1-xCo_xO crystals at 300 K was obtained, and showing room-temperature ferromagnetism. The Zn_1-xNi_xO crystal's magnetization rate do not decrease as the temperature rises under room temperature, the hysteresis loop of Zn_1-xNi_xO crystals was obtained at 300K, the crystals show room-temperature ferromagnetism. The Zn_1-xFe_xO crystal's magnetization rate decrease as the temperature rises at room temperature, it has no ferromagnetism. When the Cu was co-doped with the Fe, under the room temperature, the magnetization varies unobviously as the temperature rises. The hysteresis loop of Zn_1-xFe_xO crystals at 300 K was obtained, and show room-temperature ferromagnetism. The Zn_1-xSn_xO crystals show paramagnetism.