Crystallization kinetics and magnetic properties of iron oxide contained 25Li2O–8MnO2–20CaO–2P2O5–45SiO2 glasses

With crystallization at 850 °C for 4 h, LiMn2O4, β-wollastonite (β-CaSiO3), lithium silicate (Li2SiO3), Ca(Ca, Mn)Si2O6 and Li2Ca4Si4O13 phases were found in 25Li2O–8MnO2–20CaO–2P2O5–45SiO2 (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 β-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)ferrite particle sizes in the glass ceramics containing 8 at.% Fe2O3 varied from a few μm 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.