Title :
The annealing temperature dependence of magnetic properties in Sr-ferrite nanoparticles
Author :
Lee, Sang Won ; An, Sung Yong ; Kim, Chul Sung ; Shim, In-Bo ; Chul Sung Kim
Author_Institution :
Dept. of Phys., Kookmin Univ., Seoul, South Korea
Abstract :
The SrFe12O19 powders prepared by a sol-gel method were annealed at temperatures ranging from 400°C to 900°C for 3 h and 6 h in air. Magnetic and structural properties of the powders were characterized with a vibrating sample magnetometer (VSM), X-ray diffractometer (XRD), scanning electron spectroscopy (SEM), Mossbauer spectroscopy, thermogravimetry (TG), and differential thermal analysis (DTA). M-type hexagonal phase is observed in the samples annealed at temperatures above 600°C by XRD. In the sample annealed at 800°C, lattice constants are a0=5.9227 Å c0=23.2368 Å and particle size was about 74 nm. The coercivity of the samples increased from 6.2 Oe for the powder annealed at 500°C to 7000 Oe for annealed powder at 800°C. The saturation magnetization increased from 30.7 emu/g to 63.0 emu/g as annealing temperature is increased from 500°C to 800°C.
Keywords :
Mossbauer effect; X-ray diffraction; annealing; coercive force; differential thermal analysis; ferrites; lattice constants; magnetic particles; magnetisation; nanoparticles; particle size; scanning electron microscopy; strontium compounds; thermal analysis; 3 h; 400 to 900 degC; 6 h; 74 nm; DTA; Mossbauer spectroscopy; SEM; Sr-ferrite nanoparticles; SrFe12O19; VSM; XRD; annealing temperature dependence; coercivity; differential thermal analysis; lattice constants; magnetic properties; particle size; saturation magnetization; structure; thermogravimetry; Annealing; Magnetic properties; Magnetometers; Nanoparticles; Powders; Saturation magnetization; Spectroscopy; Temperature dependence; Temperature distribution; X-ray scattering;
Journal_Title :
Magnetics, IEEE Transactions on
DOI :
10.1109/TMAG.2003.815741
