Commercially available niobium (V) oxide [Nb2O5], with barium acetate [Ba(CH3COO)2] and magnesium acetate [Mg(CH3COO)2-4H2O] was used as the starting material in the sol-gel process for preparing Ba(Mg1/3Nb2/3)O3 (BMN...Commercially available niobium (V) oxide [Nb2O5], with barium acetate [Ba(CH3COO)2] and magnesium acetate [Mg(CH3COO)2-4H2O] was used as the starting material in the sol-gel process for preparing Ba(Mg1/3Nb2/3)O3 (BMN) nanopowders. At first, Nb2O5 reacted with melting sodium hydroxide and transformed into dispersible oxide. The resulting glassy substance after cooling was dispersed and washed several times in distilled water to remove the Na+ ions. The as-prepared colloidal Nb2O5-nH2O was subsequently mixed with acetic solution of barium acetate and magnesium acetate according to the required molar proportions and followed by gelation. The ultrafine BMN powders were finally obtained after heat-treating the gel at 820℃for 1 h, and the as-sintered nanoceramics revealed a high relative density of 98.2%, and a high microwave Q-factor, of 10397 at 1.45GHz.展开更多
借助典型的固相反应烧结机制，研究了MgO含量对微波高品质因数瓷介材料微观结构与介电性能参数影响的规律。结果表明：高温烧结的镁钛系瓷介质中，随着MgO含量增加，Mg 2 TiO 4晶相的含量逐渐降低、瓷体晶粒由尖晶石型演变为氯化钠型结...借助典型的固相反应烧结机制，研究了MgO含量对微波高品质因数瓷介材料微观结构与介电性能参数影响的规律。结果表明：高温烧结的镁钛系瓷介质中，随着MgO含量增加，Mg 2 TiO 4晶相的含量逐渐降低、瓷体晶粒由尖晶石型演变为氯化钠型结构，对应的微波介电常数出现缓慢降低，在10.10~13.37范围连续可调。当x=16时，在1525℃/2 h烧成，可获得性能优良的（2＋x）MgO-TiO2陶瓷，其ρ=3.49g·cm–3，εr=10.37，Q·f=118747 GHz（f=10.47 GHz），τf=–53.35×10–6℃–1。展开更多
文摘Commercially available niobium (V) oxide [Nb2O5], with barium acetate [Ba(CH3COO)2] and magnesium acetate [Mg(CH3COO)2-4H2O] was used as the starting material in the sol-gel process for preparing Ba(Mg1/3Nb2/3)O3 (BMN) nanopowders. At first, Nb2O5 reacted with melting sodium hydroxide and transformed into dispersible oxide. The resulting glassy substance after cooling was dispersed and washed several times in distilled water to remove the Na+ ions. The as-prepared colloidal Nb2O5-nH2O was subsequently mixed with acetic solution of barium acetate and magnesium acetate according to the required molar proportions and followed by gelation. The ultrafine BMN powders were finally obtained after heat-treating the gel at 820℃for 1 h, and the as-sintered nanoceramics revealed a high relative density of 98.2%, and a high microwave Q-factor, of 10397 at 1.45GHz.
