纳米颗粒NiFe_2O_4的穆斯堡尔谱研究  

Mossbauer studies of NiFe_2O_4 nanoparticles

作　　者：刘锦宏[1] 王丽[1] 薛萍萍[1] 温福昇[1] 李发伸[1] 

机构地区：[1]兰州大学磁学与磁性材料教育部重点实验室,甘肃兰州730000

出　　处：《兰州大学学报（自然科学版）》2005年第1期78-81,共4页Journal of Lanzhou University(Natural Sciences)

摘　　要：用溶胶凝胶法制备了NiFe2O4纳米晶粉末样品,用XRD表征了样品的晶体结构,用谢乐公式估算了纳米晶粒的尺寸;分别在室温,80 K,9 K采集了样品的穆斯堡尔谱,对样品中超精细场的变化及Fe3+离子在A,B两个晶位的占位情况进行了研究.结果发现随着晶粒尺寸的减小,超精细场变小,Fe3+占据B位的比例增大,纳米颗粒呈现混合型尖晶石结构,不同于块体材料完全反型的尖晶石结构.Nanocrystalline NiFe204 particles were prepared by sol-gel method. XRD was used to determine the structure, phase purity and particle size. We noticed the variation of the integrated intensity ratio of I(220)/I(222) in XRD patterns. The origin of these phenomena was proposed to be the redistribution of cations between A and B sites in the spinel structure. Further study of Mossbauer spectroscopy confirmed the proposal. Mossbauer spectra were collected at room temperature, 80 K and 9 K, respectively. The variation of the hyperfine magnetic field and the occupancy of cations on A and B sites were studied. It has been found that, with the decrease of the particle size, the population of Fe3+ ions increases on A site and decreases on B site. Measured value of the cation distribution suggests a mixed spinel structure, which is different from the value for the inverse spinel of the bulk material.

关 键 词：溶胶凝胶 纳米颗粒 NIFE2O4 穆斯堡尔谱 

分 类 号：O482.54[一般工业技术—材料科学与工程]