Co掺杂量对Ti1-xCoxO2纳米颗粒结构及磁性的影响

摘要

以钛酸丁酯、六水硝酸钴等为原料,采用溶胶凝胶法合成Ti1-xCoxO2干凝胶前驱体,将前驱体在500℃空气氛围下进行退火处理,得到一系列Ti1-xCoxO2纳米颗粒样品.采用差热/热重综合热分析仪(TG-DTA)、X射线衍射仪(XRD)、拉曼光谱(Raman)和振动样品磁场计(VSM)对样品的结构和磁性进行研究.结果表明,经500℃退火温度处理后,样品为锐钛矿结构.当Co离子含量超过5％时,样品开始析出杂相CoTiO3.Co掺杂量对样品的磁性也有影响,当x≤0.050时,样品在中心区域均出现明显的磁滞现象,并且样品的磁性随着Co掺杂量的增多而增强.当x＞0.050,样品的磁性变成顺磁性.%Ti1-xCoxO2 nanoparticleswere synthesized by annealing dry gel in the air. The Ti1-xCoxO2 dry gel was produced by the reaction mainly between Tetra-n-butyl Titanate and cobaltous nitrate. The crystal structure and the magnetic properties of the Ti1-xCoxO2 nanoparticles were investigated by thermogravimetry-differential thermal analysis (TG-DTA) , X-ray diffraction (XRD) patterns, Raman spectroscopy and vibrating sample magnetometer (VSM). It was found that the Co doped TiO2 nanopartilce is anatase structure when the annealing temperature is 500°C. A phase of CoTiO3 began to appear when the content of Co was higher than 5%. Also, the content of Co element has the effect on the magnetic properties of the samples. When x≤0. 050, the magnetic properties increased with the increase of the Co content. When x＞0. 050, a transition from ferromagnetism to paramagnetism could be observed.