Ni掺杂ZnO的结构、光学和磁学性质

Structure Optical and Magnetic Properties of Ni-doped ZnO Powders Prepared by Sol-gel Technique

利用溶胶-凝胶法制备了Zn1-xNixO(x=0.1%,0.4%,0.7%,1.0%)粉末,研究了样品的结构、光学和磁学性质.X射线衍射表明所有样品都具有纤锌矿结构,没有发现第2相.随着掺杂量的增加c轴晶格常数变小.X射线光电子能谱显示样品中的Ni离子处于+2价态.由紫外可见光吸收谱发现,随着掺杂量的增加能隙逐渐变小,证实了Ni2+对Zn2+的替代.由光致发光谱发现,在390 nm附近出现了由于近带边自由激子复合引起的紫外峰和以467 nm为中心宽带深能级发光带组成的由缺陷引起的较宽的蓝光.磁化强度测量表明,样品具有室温铁磁性,且随着掺杂浓度的增加,饱和磁化强度增加.当掺杂量为1.0%时饱和磁化强度最大为0.076μB/Ni.

（x = 0.1%, 0.4 %, 0.7 %, 1.0 96 ）powders have been prepared by sol-gel. The structural, optical and magnetic properties of powders have been investigated. X-ray diffraction measurements have shown that Nidoped ZnO has the expected wurzite structure and the c-axis lattice constants decrease as doped Ni increase. Xray photoelectron spectroscopy results have revealed that the Ni ion is in a ＋ 2 charge state in the samples. The optical absorption spectra has revealed that the band-gap energy of Zn1-xNixO is decreased with increasing Ni concentration,which is presumably induced by Ni^2＋ substitution. Photoluminescence （PL） measurements of Nidoped samples have illustrated the UV-PL emission centered at about 390 nm which is ascribed to the near-band dege （NBE） emissions of ZnO-like band structures. A broad peak at a wavelength centered at about 467 nm has also been observed which indicates the presence of a greater fraction of defect （oxyen intersitial） in ZnO. Magnetization measurements have shown that Ni-doped ZnO have the room-temperature ferromagnetism. The saturated magnetization increases as Ni concentration increase and a largest saturted magnetization is 0. 076μB/Ni concentration is 1.0 %.