摘要
采用溶胶-凝胶法制备了Cr-Fe共掺CeO_(2)(Ce_(0.99-x)Cr_(x)Fe_(0.01)O_(2),x=0,0.01,0.02,0.03)纳米颗粒,对其结构及物相、形貌尺寸和磁学性能进行分析研究。XRD和Raman研究表明,Cr-Fe共掺CeO_(2)纳米颗粒未破坏CeO_(2)原有的立方萤石晶体结构,且样品中没有第二相出现。随着Cr掺杂浓度的增大,晶粒尺寸减小,结晶质量下降。SEM照片显示纳米颗粒呈球形,且尺寸均匀,分散性好,颗粒大小在20 nm左右。磁性测试结果表明,在磁场强度为10 kOe时,样品在低温(10 K)下的磁化强度大于室温(300 K)。所有磁性测量都表现出磁滞现象,表明样品具有低温和室温铁磁性能。随着Cr掺杂量的增加,矫顽力及在磁场强度为10 kOe时的磁化强度明显提高。结合XRD和Raman研究结果,可以认为样品的铁磁性属于Cr-Fe共掺CeO_(2)纳米颗粒的本征性能。
In this paper,Cr-Fe co-doped CeO_(2)(Ce_(0.99-x)Cr_(x)Fe_(0.01)O_(2),x=0,0.01,0.02,0.03)nanoparticles were prepared by sol-gel method.The structure,morphology and magnetic properties of these nanoparticles were investigated by X-ray diffraction(XRD),scanning electron microscopy(SEM),Raman spectroscopy(Raman)and comprehensive physical property measurement system(PPMS).XRD and Raman studies show that Cr-Fe co-doped CeO_(2)nanoparticles have single-phase with cubic fluorite crystal structure,which are the same as pure cubic phase of CeO_(2)structures.This result indicates that Cr-Fe co-doping does not form any other oxide related to Cr or Fe,and there is no ferromagnetic second phase in these samples.With the increase of Cr doping concentration,the grain size and crystal quality decrease.SEM images show that the nanoparticles are spherical in shape,uniform in size and good in dispersion.The particle size is about 40 nm.The magnetic test results show that the magnetization at 10 kOe magnetic field of Cr-Fe co-doped CeO_(2)nanoparticles have a large value at low temperature,but it decreases at room temperature.All magnetic measurements show hysteresis phenomenon,which indicates that the samples have low temperature and room temperature ferromagnetic properties.With the increase of Cr content,the coercivity and the magnetization at 10 kOe magnetic field increase obviously.Combined with the results of XRD and Raman,it can be considered that the ferromagnetism of the samples belongs to the intrinsic properties of Cr-Fe co-doped CeO_(2)nanoparticles.
作者
阳生红
蒋志洁
张曰理
YANG Sheng-hong;JIANG Zhi-jie;ZHANG Yue-li(School of Physics,Sun Yat-sen University,Guangzhou 510275,China;School of Materials Science and Engineering,Sun Yat-sen University,Guangzhou 510275,China)
出处
《磁性材料及器件》
CAS
CSCD
2021年第2期1-5,共5页
Journal of Magnetic Materials and Devices
基金
国家自然科学基金资助项目(61176010,61172027)。
