J. Phys. IV France 07 (1997) C1-553-C1-554
Lithium Ferrite Nanocrystals Embedded in a non-Magnetic Glass MatrixE. Rezlescu, N. Rezlescu and M.L. Craus
Institute of Technical Physics, Bd. Mangeron 47, 6600 Iasi, Romania
Nanocrystalline LiFe5O8 particles embedded in an amorphous matrix were obtained by heat treatments of the non-magnetic oxide glass 32Li2O-8FeO3-60B2O3, between 200 and 770°C. The X-ray spectra reveal the formation of the spinel phase of Li-ferrite in the initially amorphous materials only for annealing temperatures higher than 440°C and the hybrid structure becomes more evident with the increase of temperature. The occurrence of the magnetic spinel phase (LiFe5O8) was proved by magnetization and Curie temperature measurements too. The evolution of the magnetic properties of these glass-ceramic compounds in terms of annealing temperature was investigated. The magnetic properties (σs, Hc) are correlated with the average size of the LiFe5O8 nanoparticles dispersed in the glass matrix. The X-ray diffraction data indicated an evident increase in the average crystal block size from 3.5 to 50 nm with the increase of annealing temperature from 440° to 770°C.
© EDP Sciences 1997