摘要
以FeSO4 ·7H2 O和NiSO4 ·7H2 O为原料 ,首先制备出颗粒细小的碱式碳酸盐前驱体 ,在 30 0～ 70 0℃焙烧 1h后 ,制备出铁酸镍纳米晶 ,粒径为 8～ 54nm ,粒度均匀。通过测量它的比饱和磁化强度σs 与比表面积Sa,得出经验公式σs(Sa) =σs(∞ ) ( 1-aSa) ,运用非共线磁结构理论很好地解释了上述经验公式 ,并得到纳米晶的非共线表面层的厚度。
A basic carbonate precursor with very fine particles was synthesied by using FeSO 4·7H 2O and NiSO 4·7H 2O, and NiFe 2O 4 nanocrystallites were then obtained by calcining the precursor. The results of XRD and TEM analysis show the NiFe 2O 4 nanocrystallites with spherical shape are even, and their average diameters increase from 8nm to 54nm when the precursor is calcined at 300—700℃ for 1h. Their specific saturation magnetization σ s and specific surface area S a were measured. A empirical formula σ s(S a)=σ s(∞)(1-aS a) was obtained which can be interpreted very well by a noncollinear magnetic structure model, and the value of the canted layer thickness was deduced.
出处
《材料科学与工程》
CSCD
北大核心
2001年第1期86-89,共4页
Materials Science and Engineering
基金
安徽省自然科学基金
