熔盐法合成Na_(0.5)K_(0.5)NbO_3粉体(英文)

The preparation of(Na_(0.5)K_(0.5))NbO_3 powder by molten salt synthesis

采用熔盐法在K2CO3和Na2CO3的熔盐(K2CO3/Na2CO3=45/55)中800℃并保温2h的条件下制备出了单相、纯钙态矿型结构的Na0.5K0.5NbO3粉体,运用XRD以及SEM技术对所得粉体进行了相组成及显微结构分析.结果表明:随着盐含量的增加,晶体结构从正交相转变为四方相,晶粒大小先增加而后稍微减小,并且获得较好的介电压电性:εT33/ε0(1kHz)=45～264,tgδ=1.5%～2.6%,Tc=402℃,TT-o=202℃,d33=88～98pC/N,Qm=465～574,Kp=29.09%～30.47%,在10kHz频率下,介电损耗有一点改变.NKN将有可能成为用于高频下的无铅压电陶瓷之一.

The （Na0.5 K0.5 ） NbO3 powder with single-phase, pure perovskite was prepared at 800℃ for 2h in molten salt （K2CO3 / Na2 CO3=45/55） ,which was characterized by the X-ray diffraction and SEM technique. It was found that the crystal structure changes from orthorhombic phase to tetragonal phase and grain size increases and then reduces a little with the increasing of salt. Good dielectric and piezoelectric properties can be observed： ε33^T/ε0（1kHz）=45-264,tgδ=1.5%～2.6%,Tc=402℃,Tτ-o=202℃,d33=88-98pC/N,Qm=465-574,Kp=29.09%～30.47% and in the frequency of 10kHz, the dielectric loss changed a little.