【摘要】 采用普通的固相反应烧结方法制备了(KxNa1-x)NbO3(KNN,x=0.40～0.70)和(Na0.485K0.485Li0.03)(Nb0.80Ta0.20)O3(NKLNT)陶瓷,研究了它们的介电和压电性能.发现KNN陶瓷的室温下的压电常数d33在0.4≤x≤0.65范围基本不依存于K和Na间的组分比、分布在100～130pC/N之间,而与陶瓷密度密切相关,但介电常数和介电损耗则随K组分含量的增加而降低.NKLNT陶瓷呈现出较高的d33,kp和kt值,然而介电损耗较大.添加了适量烧结助剂K5.4Cu1.3Ta10O29(KCT)的KLNT-KCT陶瓷致密度有显著的提高,相对密度大于96%,呈现出良好的压电性能,其d33达到215pC/N,kp=48%,kt=47%,tgδ≤0.75%.研究表明碱金属铌酸盐陶瓷是一类有发展前景的无铅压电材料.更多还原

【Abstract】 (K_ x Na_ 1-x )NbO_ 3 (KNN, x=0.40～0.70) and (Na_ 0.485 K_ 0.485 Li_ 0.03 )(Nb_ 0.80 Ta_ 0.20 )O_ 3 _ (NKLNT) ceramics are prepared using traditional solid-state reaction method, and their dielectric and piezoelectric properties are investigated. Further, the efficiency of a sintering aid K_ 5.4 Cu_ 1.3 Ta_ 10 O_ 29 (KCT) is examined for NKLNT. The results show that the piezoelectric constant d_ 33 has little dependence on the compositional ratio between K and Na within 0.4 ≤ x ≤ 0.65 in KNN, distributing in the range of 100pC/N to 130pC/N which are higher than that previously reported in literature. However, both the dielectric constant and the loss tangent decrease with x. NKLNT shows the comparatively high values of d_ 33 , k_ p and k_ t ,but also the large dielectric loss and the low comparative density. It has been found that incorporating small amount of KCT in NKLNT could enhance the comparative density and accordingly the piezoelectric performance, of which d_ 33 =215 pC/N, k_ p =48%, k_ t =47% and tgδ≤0.75%. Thus, alkali niobate ceramics is a promising lead-free piezoelectric material.更多还原