PMN-PNN-PT单晶的固相法生长研究

Study on Pb(Mg_(1/3)Nb_(2/3))O_3-Pb(Ni_(1/3)Nb_(2/3))O_3-PbTiO_3 Crystals by Solid State Growth

采用两步法和埋入PMN-PT单晶为模板的等离子放电烧结(SPS)技术制备出了致密的单一钙钛矿相的PMN-PNN-PT陶瓷,随后在1200℃下退火100h来诱导晶体的生长。实验结果表明,PMN-PNN-PT单晶<111>方向的生长速度明显快于<001>方向,而<111>方向生长的晶体形状为V字形,这是由钙钛矿结构的生长机理决定的,钙钛矿结构晶体的生长是通过<001>方向的层状生长来实现的。

A small piece of （001） or （111） Pb（Mg1/3Nb2/3）O3-PbTiO3 （PMN-PT） seed crystals was embedded in Pb（Mg1/3Nb2/3）O3 -Pb（Ni1/3Nb2/3）O3-PbTiO3 （PMN-PNN-PT） polycrystalline matrix to form the fully dense disk by spark plasma sintering technique. Specimens were subsequently annealed at 1200 ℃ for 100 h to induce crystal growth. The results show that growth in the 〈1 1 1〉 direction is faster than in the 〈00 1〉 direction, and the 2D morphology with V-shaped single crystals of PMN-PNN-PT were also observed when the （111） seeds plate was used which may indicate the layer growth mechanism for the {100} faces.