Bi_2O_3-ZnO-Nb_2O_5系中焦绿石结构与相分布

PROCHLORE PHASE AND DISTRIBUTION IN Bi_2O_3-ZnO-Nb_2O_5 SYSTEM

根据焦绿石结晶化学原理，研究了Bi2O3－ZnO－Nb2O5（BZN）系中焦绿石的相结构与分布用淬冷技术保持样品的高温相结构，用粉末X-射线衍射技术（XRD）分析相组成与相结构得到了BZN系中两种焦绿名单相（立方相α和正交相β和α-β复相分布的等温相图。

The pyrochlore structure and phase distribution in Bi2O3-ZnO-Nb2O5(BZN) system were investigated. According to the principles of the crystal chemistry of pyrochlore, the possible pyrochlore area in BZN system was selected for study. The samples were quenched after calcining to maintain their phase structures at high temperatures. The phase stucture and phase constitution were analyzed by X-ray diffraction (XRD) technology. The isothermal phase diagram at 1000℃ about tWo pyrochlore structures (cubic phase α and orthorhombic phase β) and the α-β biphase have been obtained. The mechanism of the α-β displacive phase transformation has also been discussed.