Physical and magnetic properties of highly aluminum doped strontium ferrite nanoparticles prepared by auto-combustion route

详细信息	查看全文 | 推荐本文 |

• 作者：H. Luo^a ; B.K. Rai^a ; S.R. Mishra^a ; ^{srmishra@memphis.edu} ; V.V. Nguyen^b ; J.P. Liu^b
• 关键词：Hexaferrite ; doped hedxaferrite ; Sr-Hexaferrite ; Al doped Sr-Ferrite ; High Coercivity Ferrite
• 刊名：Journal of Magnetism and Magnetic Materials
• 出版年：2012
• 期刊代码：31_03048853
• 类别：ph
• 出版时间：August, 2012
• 卷：324
• 期：17
• 页码：2602-2608
• 文件大小：663 K

摘要

Highly Al³⁺ ion doped nanocrystalline SrFe_12鈭?em>xAl_xO₁₉ (0鈮?em>x鈮?2), were prepared by the auto-combustion method and heat treated in air at 1100 掳C for 12 h. The phase identification of the powders performed using x-ray diffraction show presence of high-purity hexaferrite phase and absence of any secondary phases. With Al³⁺ doping, the lattice parameters decrease due to smaller Al³⁺ ion replacing Fe³⁺ ions. Morphological analysis performed using transmission electron microscope show growth of needle shaped ferrites with high aspect ratio at Al³⁺ ion content exceeding x鈮?. Al³⁺ substitution modifies saturation magnetization (M_S) and coercivity (H_C). The room temperature M_S values continuously reduced while H_C value increased to a maximum value of 18,100 Oe at x=4, which is an unprecedented increase (鈭?21%) in the coercivity as compared to pure Sr-Ferrite. However, at higher Al³⁺ content x>4, a decline in magnetization and coercivity has been observed. The magnetic results indicate that the best results for applications of this ferrite will be obtained with an iron deficiency in the stoichiometric formulation.