Al^3+取代对低饱和磁化强度钇铁石榴石铁氧体烧结特性的影响

Effects of Al^3+substitution on the sintering behavior of low saturation magnetization yttrium iron garnet ferrite

采用传统氧化物陶瓷工艺制备低饱和磁化强度(4πMs)钇铁石榴石铁氧体,研究不同烧结温度时Al3+取代对材料气孔率(P)和收缩率(η)等烧结性能的影响。根据不同烧结温度样品收缩率的拟合直线计算Al3+取代样品的烧结活化能,并结合热重-差热(TG-DSC)联合分析研究Al^3+取代量对活化能的影响机制。结果表明,Y3Al5O12铁氧体的成相温度高于Y3Fe5O12铁氧体的成相温度;1420℃烧结时,随着Al3+取代量x由0.6增大至1.4,烧结活化能从191 kJ/mol增大到257 kJ/mol,烧结更加困难,烧结样品的P从1.63%增大到3.60%,η从16.62%减小到14.38%。

Low saturation magnetization(4πMs)yttrium iron garnet ferrite was prepared by traditional oxide ceramic process and the effects of Al^3+substitution on the sintering properties such as porosity(P)and shrinkage(η)at different sintering temperatures were investigated.The sintering activation energy of Al^3+substituted sample was calculated based on the fitting straight line of sample shrinkage at different sintering temperatures.The mechanism of the effects of Al3+substitution on activation energy was studied via the thermogravimetric-differential scanning calorimetry(TG-DSC)analysis.The results show that the phase formation temperature of Y3Al5O12 ferrite is higher than that of Y3Fe5O12 ferrite.Sintered at 1420℃,as the Al3+substitution amount increases from 0.6 to 1.4,the sintering activation energy increases from 191 kJ/mol to 257 kJ/mol,so sintering solid-phase reaction becomes more difficult.As a result,the P of the samples increases from 1.63%to 3.60%,and theηdecreases from 16.62%to 14.38%.