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分别研究了不同含量Li_2CO3/V_2O5共掺杂和部分Li取代Mg对Mg_4Nb_2O9基陶瓷烧结特性、显微结构和微波介电性能的影响。结果表明: Li_2CO3/V_2O5共掺杂或部分Li取代Mg,均能使Mg_4Nb_2O9基陶瓷的烧结温度从1 400℃降至950℃,但其烧结机理不同。Li_2CO3/V_2O5共掺杂Mg_4Nb_2O9(MNLV)样品中的低熔点液相,使MNLV陶瓷的致密化烧结温度降低。部分Li取代Mg显著降低了(Mg4-xLix)(Nb1.92V0.08)O9-δ(MLNV)样品的致密化烧结温度。950℃烧结,相对于MNLV样品的品质因数(Q=13 276)而言,MLNV样品的Q值(1 759)显著恶化,这是由于Li1+占据Mg2+晶格,使晶体中非谐振项损耗增加。
Abstract：The sintering behavior,microstructures and microwave dielectric properties of Mg_4Nb_2O9 matric ceramics with Li_2CO3/V_2O5 co-doped and small amount of Li1+ substitution for Mg2+ were investigated,respectively.The results show that the addition of Li_2CO3/V_2O5 or Li1+ substitution for Mg2+ in Mg_4Nb_4O9 matric ceramics lowers the sintering temperature from 1400℃to 950℃,but the sintering mechanisms are different.A liquid phase could be responsible for enhanced sintering in Mg_4Nb_2O9 sample(MNLV) combined with Li_2CO3/V_2O5.The densification temperature for sample(Mg4-xLix)(Nb1.92V0.08)O9-δ(MLNV) becomes lower due to the decreased temperature of liquidus according to the substitution of Li for Mg ions.The quality factor of sample MLNV(1 759) sintered at 950℃is degraded drastically,compared to that of sample MNLV(13 276),which can be attributed to the increase of anharmonic -interaction-effect dielectric loss caused by Li1+ substitution for Mg2+.
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基本信息:
中图分类号:TQ174.1
引用信息:
[1]姚国光,裴翠锦,田秀劳.低温烧结Mg_4Nb_2O_9微波介质陶瓷(英文)[J].硅酸盐学报,2009,37(06):1017-1021.
基金信息:
国家自然科学基金(50572060;ZL2008-33)资助项目。
2009-06-15
2009-06-15