The role of Dy3+ ions and sintering temperature on the magnetic characterization of LiCo-Ferrite

Four groups of the series of rare earth ferrite Li0.5+zCozRXFe2.5-2z-xO4; z = 0.1, (x = 0.0, 0.025, 0.05..., ... and 0.2) and R is Dy were prepared using the standard ceramic technique at sintering temperatures 1373, 1423, 1473 and 1523 K. The magnetic parameters were calculated from the measurement of the magnetic susceptibility in the temperature range (300-900 K) using Faraday's method at five different magnetic field intensities of (1275-2922 Oe). The obtained data for the Curie temperature (T-C) and the effective magnetic moment (mu(eff)) clarify that the suitable sintering temperature was 1473 K and the critical dysprosium content was x = 0.075. The appearance of hysteresis loop in the ferromagnetic region of the relation of magnetic susceptibility vs. temperature during the heating and cooling of two runs is interpreted in view of the thermal energy that disturbs the aligned magnetic dipoles. (C) 2004 Elsevier B.V. All rights reserved.