Low temperature sintering behavior of La-Co substituted M-type strontium hexaferrites for use in microwave LTCC technology  

作　　者：黄太星 彭龙 李乐中 王瑞 胡云 涂小强 

机构地区：[1]Sichuan Province Key Laboratory of Information Materials and Devices Application, Chengdu University of Information Technology

出　　处：《Journal of Rare Earths》2016年第2期148-151,共4页稀土学报（英文版）

基　　金：supported by the National Public Welfare Fund Industry Research(201410026);Scientific Research Foundation of Education Office of Sichuan Province(13Z198);the Young and Middle-aged Academic Leaders of Scientific Research Funds of Chengdu University of Information Technology(J201222)

摘　　要：The La-Co substituted Sr1–xLaxFe12–xCoxO19 (x=0–0.5) ferrites with appropriate Bi2O3 additive were prepared by conventional sintering method and microwave sintering method at low sintering temperatures compatible with LTCC (low temperature co-fired ceramics) systems, and their sintering behavior was chiefly investigated, including the crystal structure, saturation magnetizationMs, magnetic anisotropy fieldHa, intrinsic coercivityHci, and Curie temperatureTC. Experiment results clearly showed that the pure M-type crystal phase was successfully obtained when the La-Co substitution amountx did not exceed 0.3. However, the single M-type phase structure transformed to multiphase structure with further increased x, where the M-type phase coexisted with the non-magnetic phase such asα-Fe2O3 phase, La2O3 phase, and LaCoO3 phase. Appropriate La-Co substitution improved theMs (>62 emu/g),Ha (>1400 kA/m), andHci (>320 kA/m) for the ferrites withx varying from 0.1 to 0.3, but theTC decreased with increasing substitution amount. More-over, the microwave sintered ferrites could provide largerHci and similarMs compared with the conventional sintered ferrites.The La-Co substituted Sr1–xLaxFe12–xCoxO19 (x=0–0.5) ferrites with appropriate Bi2O3 additive were prepared by conventional sintering method and microwave sintering method at low sintering temperatures compatible with LTCC (low temperature co-fired ceramics) systems, and their sintering behavior was chiefly investigated, including the crystal structure, saturation magnetizationMs, magnetic anisotropy fieldHa, intrinsic coercivityHci, and Curie temperatureTC. Experiment results clearly showed that the pure M-type crystal phase was successfully obtained when the La-Co substitution amountx did not exceed 0.3. However, the single M-type phase structure transformed to multiphase structure with further increased x, where the M-type phase coexisted with the non-magnetic phase such asα-Fe2O3 phase, La2O3 phase, and LaCoO3 phase. Appropriate La-Co substitution improved theMs (>62 emu/g),Ha (>1400 kA/m), andHci (>320 kA/m) for the ferrites withx varying from 0.1 to 0.3, but theTC decreased with increasing substitution amount. More-over, the microwave sintered ferrites could provide largerHci and similarMs compared with the conventional sintered ferrites.

关 键 词：M-type hexaferrites SrFe12O19 ferrites La-Co substitution low temperature sintering LTCC rare earths 

分 类 号：TQ174.7[化学工程—陶瓷工业]