Crystallization kinetics and magnetic properties of iron oxide contained 25Li(2)O-8MnO(2)-20CaO-2P(2)O(5)-45SiO(2) glasses

With crystallization at 850 degrees C for 4 h, LiMn2O4, P-wollastonite (beta-CaSiO3), lithium silicate (Li2SiO3), Ca(Ca, Mn)Si2O6 and Li2Ca4Si4O13 phases were found in 25Li(2)O-8MnO(2)-20CaO-2P(2)O(5)-45SiO(2) (LMCPS) glass ceramics. The (Li, Mn)ferrite phase was obtained in the iron oxide contained LMFCPS glass ceramic and Li2FeMn3O8 phase was found in that containing 8 at.% Fe2O3. TEM investigations showed that (Li, Mn)ferrite particles dispersed in the P-wollastonite matrix (Li, Mn)ferrite particles, with an average size of 40 nm, were found in the glass ceramics containing 4 at.% Fe2O3. The (Li, Mn)feffite particle sizes in the glass ceramics containing 8 at.% Fe2O3 varied from a few mu m to 5 nm. The SQUID result showed that only the glass ceramic containing 4 at.% Fe2O3 exhibited super-paramagnetic behavior at temperature 300 K and ferromagnetic behavior at 4 K. The LMCPS glass ceramic containing 8 at.% Fe2O3 exhibited ferromagnetic behavior at both temperatures. (C) 2006 Elsevier Ltd. All rights reserved.