(K,Na) (Nb,Ta,Sb)O3粉体制备及陶瓷介电性能研究

Ta/Sb掺杂的K0.5Na0.5Nb0.7TaxSb0.3-xO3(KNNSTx,x＝0.06,0.09,0.12,0.15,0.18,0.21, 0.24)粉体经水热合成,Ta、Sb对粉体物相、微观结构的影响被系统研究,烧结后陶瓷的微观结构、介电性能表明:陶瓷物相均具有纯钙钛矿结构;随着Ta含量的增加陶瓷晶粒尺寸逐渐增大,x＝0.09、0.12时较小粒径颗粒均匀分布在大颗粒的空隙之间,陶瓷密度增加;样品的介电常数随着Ta含量的增加x＝0.06～0.12逐渐降低,x＝0.15～0.24逐渐增加,居里温度均在350 ℃左右,且x＝0.09、0.12时陶瓷介电损耗较小.

Powders Preparation and Dielectric Properties of (K,Na) (Nb,Ta,Sb) O3 Ceramics

Sb/Ta co-doped lead-free K0.5Na0.5Nb0.7TaxSb0.3-xO3(abbreviated KNNSTx, x＝0.06, 0.09, 0.12, 0.15, 0.18, 0.21, 0.24) were synthesized using the hydrothermal method.The influence of Ta, Sb content on phase、morphology of powders were systematically studied.The results of microstructure, dielectric properties of sintered KNNSTx ceramics from the obtained powders show that: the KNNSTx ceramics exhibit pure perovskite structure; the partical size become larger as Ta content increases, when x＝0.09, 0.12 the fine grains fill the gaps between large grains, make enhancing ceramic density; The dielectric constant first decrease as Ta content increases from x＝0.06 to 0.12 and then increase with from x＝0.15 to 0.24, and the cure temperature is all at about 350 ℃, x＝0.09, 0.12 both have lower dielectric loss.