Crystallographic and magnetic properties of TixCo1+xFe2-2xO4 ferrite powders
Crystallographic and magnetic properties of TixCo1+xFe2-2xO4 ferrite powders
复制标题
DOI：
10.1016/s0304-8853(01)00260-8
复制
发表时间：
2001-07-01
影响因子：
2.7
通讯作者：
Lee, YB
中科院分区：
文献类型：
--
作者：
Chae, KP;Kim, WK;Lee, YB
采用溶胶-凝胶法制备了TixCo 1 + xFe 2 - 2xO 4（0.0 ≤ x ≤ 0.7）铁氧体粉末。用X射线衍射、穆斯堡尔谱和振动样品磁强计研究了粉末的颗粒生长、晶体学和磁性。TixCo_（1 + x）Fe_（2 - 2 x）O_4（x = 0.2）铁氧体粉末在873 K以上退火后只有单一的尖晶石结构，表现出铁磁性。在773 K下退火的粉末具有典型的尖晶石结构，同时显示出顺磁性和亚铁磁性。当TixCo_（1 + x）Fe_（2 - 2）O_4（x = 0.2）粉末在673 K退火时，证实了纳米晶颗粒的形成。在673 K及以上退火的粉末的磁性行为表明，在退火温度的增加产生的矫顽力的降低，相反，在饱和磁化强度的增加。在TixCo_（1 + x）Fe_（2 - 2）O_4（x = 0.2）铁氧体粉末中，最大矫顽力和饱和磁化强度分别为1564 Oe和62.6emu/g。TixCo 1-xFe 2 - 2xO 4（0.0 ≤ x ≤ 0.7）铁氧体粉末均为尖晶石结构，晶格常数随x的增大而增大。室温下的穆斯堡尔谱由两个塞曼六重态（0.0 ≤ x ≤ 0.4）组成，由于四面体和八面体位置的Fe ~（3+）离子，逐渐变为一个双峰（x = 0.7）。讨论了穆斯堡尔参数随粉末晶体学和磁性的变化。在TixCo_（1 + x）Fe_（2 - 2）O_4（0.0 ≤ x ≤ 0.7）中，超精细磁场随x的增加而减小。随着x的增加，TixCo_（1 + x）Fe_（2 - 2 x）O_4的矫顽力下降较快，而饱和磁化强度下降较慢。(C)2001 Elsevier Science B. V.保留所有权利。
The TixCo1+xFe2-2xO4(0.0 less than or equal to x less than or equal to 0.7) ferrite powders are fabricated by a sol-gel method. The growth of particles, crystallographic and magnetic properties of powders are investigated by X-ray diffraction, Mossbauer spectroscopy and vibrating sample magnetometer. TixCo1+xFe2-2xO4 (x = 0.2) ferrite powder annealed at and above 873 K have only a single spinel structure and behave ferrimagnetically. Powder annealed at 773 K has a typical spinel structure and shows a paramagnetic and ferrimagnetic nature, simultaneously. The formation of nano-crystallized particles is confirmed when TixCo1+xFe2-2xO4 (x = 0.2) powder is annealed at 673K. The magnetic behavior of powders annealed at and above 673 K shows that an increase in the annealing temperature yields a decrease in the coercivity and, in contrast, an increase in the saturation magnetization. In the TixCo1+xFe2-2xO4 (x = 0.2) ferrite powder the maximum coercivity and the saturation magnetization are 1564 Oe and 62.6 emu/g, respectively. All the structures of TixCo1-xFe2-2xO4 (0.0 less than or equal to x less than or equal to 0.7) ferrite powders are spinel, and the lattice constants increase with increasing x. The Mossbauer spectra at room temperature, consisted of two Zeeman sextets (0.0 less than or equal to x less than or equal to 0.4) due to Fe3+ ions at tetrahedral and octahedral sites, changed gradually to a doublet (x = 0.7). The variation of Mossbauer parameters with the crystallographic and magnetic properties of powders have been discussed. The magnetic hyperfine fields decrease with increasing x in TixCo1+xFe2-2xO4(0.0 less than or equal to x less than or equal to 0.7). The coercivity decreases fast but the saturation magnetization decreases slowly with increasing x in TixCo1+xFe2-2xO4. (C) 2001 Elsevier Science B.V. All rights reserved.