Mn掺杂ZnO稀磁半导体材料的制备和磁性研究

Study of synthesis and magnetic properties of Mn-doped ZnO diluted magnetic semiconductors

采用共沉淀方法制备了名义组分为Zn1-xMnxO(x=0.001,0.005,0.007,0.01)的Mn掺杂的ZnO基稀磁半导体材料,并研究了在大气气氛下经过不同温度退火后样品的结构和磁性的变化.结果表明:样品在600℃的大气条件下退火后,仍为单一的六方纤锌矿结构的ZnO颗粒材料;当样品经过800℃退火后,Mn掺杂量为0.007,0.01的样品中除了ZnO纤锌矿结构外还观察到ZnMnO3第二相的存在.磁性测量表明,大气条件下600℃退火后的样品,呈现出室温铁磁性;而800℃退火后的样品,其室温铁磁性显著减弱,并表现为明显的顺磁性.结合对样品的光致发光谱的分析,认为合成样品的室温铁磁性是由于Mn离子对ZnO中的Zn离子的替代形成的.

Co-precipitation method was employed to synthesize Mn doped ZnO dilution semiconductors Zn1- x Mnx O with the nominal composition of x = 0.001, 0.005, 0.007 and 0.01. The annealing temperature （ Ts = 400,600,700 and 800℃） dependent structure as well as the magnetic property of the produced samples were studied. The results indicated that samples sintered in air under the temperatures of 600℃ has single wurtzite ZnO structure with prominent ferromagnetism at room temperature; while in samples with the Mn nominal content of 0.007 and 0.01 sintered in air at 800℃, a second phase, namely the ZnMnO3 was observed. The sample with x = 0. 007 shows largest magnetization and coercivity. Increasing the annealing temperature to 800℃ results in decreasing of both magnetization and coercively, and the paramagnetism was enhanced. Combining with the analysis of the PL spectrum, it is reasonably concluded that the ferromagnetism observed in the studied samples originates from the doping of Mn in the lattice of ZnO crystallites.