Phase transformation and phase distribution of pyrochlore structure in Bi/sub 2/O/sub 3/-ZnO-Nb/sub 2/O/sub 5/ system

Using a quenching technique and powder X-ray diffractometry, the pyrochlore structure has been studied as a function of compositional variations. An isothermal phase diagram at 1000/spl deg/C about the pyrochlore distribution area in the Bi/sub 2/O/sub 3/-ZnO-Nb/sub 2/O/sub 5/ system has been obtained. The transformation mechanism of a cubic pyrochlore (/spl alpha/) to an orthorhombic pyrochlore (/spl beta/) has been discussed.