Substituted cobalt ferrites for sensors applications
Substituted cobalt ferrites for sensors applications
复制标题
用于传感器应用的替代钴铁氧体
DOI：
10.1016/j.jmmm.2008.04.067
复制
发表时间：
2008
影响因子：
2.7
通讯作者：
H. Chiriac
中科院分区：
文献类型：
--
作者：
O. Caltun;I. Dumitru;M. Feder;N. Lupu;H. Chiriac
本工作的目的是研究传统陶瓷方法烧结的四个系列钴铁氧体的烧结温度和取代水平对居里温度和磁致伸缩系数的影响。使用 X 射线衍射法和扫描表面电子显微镜对样品的微观结构进行表征。振动样品磁力测量和应变仪测量用于表征磁性和磁致伸缩特性。研究证明，少量的锰替代铁会大幅降低居里温度，但同时会降低比磁化强度和磁致伸缩系数。尽管有这个缺点，锰取代的钴铁氧体仍具有最大的应变导数。磁致伸缩系数的最大值还受到钴铁氧体的化学计量的影响。钴铁氧体的磁致伸缩系数可以通过用硅或锰替代小部分铁或钴来增强，这意味着应变导数以及较低磁场下的磁致伸缩的修改。最大磁致伸缩可以通过取代水平和烧结参数来调节。
The aim of this work was to study the influence of the sintering temperature and of the substitution level on the Curie temperature and on the magnetostriction coefficients for four series of cobalt ferrites sintered by conventional ceramic method. The microstructure of the samples was characterized using X-ray diffractometry and scanning surface electron microscopy. Vibrating sample magnetometry and strain gauge measurements were used to characterize the magnetic and magnetostriction properties. The study proves that a small amount of manganese substitution for iron decrease drastically the Curie temperature but in the same time decrease the specific magnetization and magnetostriction coefficient. Despite this drawback, the manganese substituted cobalt ferrites present the largest strain derivative. The maximum of the magnetostriction coefficient is also influenced by the stoichiometry of the cobalt ferrites. The magnetostriction coefficient of cobalt ferrite can be enhanced by substitution of small fraction of iron or cobalt by silicon or manganese, this implying the modification of the strain derivative as well as magnetostriction at lower magnetic fields. The maximum magnetostriction can be tuned by substitution levels and sintering parameters.