Effect of ZrO2 nucleant on crystallisation behaviour, microstructure and magnetic properties of BaO-Fe2O3-B2O3-SiO2 glass ceramics
RIS ID
22483
Abstract
Differential thermal analysis, X-ray diffractometry and scanning electron microscopy with energy dispersive spectroscopy were used to study the crystallisation of glass ribbons with a composition of 35% BaO, 35% Fe2O3, 20% B2O3 and 10% SiO2 (mol%) with 1% ZrO2 added as a nucleant. The magnetic properties of ribbons prepared via cooling the melts between steel rollers were measured with a vibrating sample magnetometer.The addition of ZrO2 apparently resulted in a quite distinct glass-in glass phase separation in as prepared specimens, greatly affecting the nucleation process.Heat treatment of specimens at their DTA exo-peak temperature of 721 C led to the formation of BaFe12O19 and BaB2O4 as the only crystalline phases. The glass ribbons heat treated in one-stage exhibited a quite non-uniform distribution of particles exhibiting exagerated grain growth, while a two-stage heat treatment at 526 and 721 C for different time periods generally led to more uniform distribution of platelet particles. The values of saturation magnetisation of specimens were in the Ms = 2329 emu/g range, while the coercivity values varied between Hc = 18003000 Oe.
Publication Details
Mirkazemi, M., Marghussian, V., Beitollahi, A., Dou, S. X., Wexler, D. Konstantinov, K. K. (2007). Effect of ZrO2 nucleant on crystallisation behaviour, microstructure and magnetic properties of BaO-Fe2O3-B2O3-SiO2 glass ceramics. Ceramics International, 33 (3), 463-469.