Pressure-induced order-disorder transition in Gd_1.5Ce_0.5Ti₂O₇ pyrochlore.

ABSTRACT: An experimental study on ordered pyrochlore structured Gd_1.5Ce_0.5Ti₂O₇ ( F d 3 ¯ m ) was carried out up to 45 GPa by synchrotron radiation X-ray diffraction and Raman spectroscopy. Experimental results show that Gd_1.5Ce_0.5Ti₂O₇ transfers to a disordered cotunnite-like phase (Pnma Z = 4) at approximately 42 GPa. Compared with the end member Gd₂Ti₂O₇, the substitution of Ce³⁺ for Gd³⁺ increases the transition pressure and the high-pressure stability of the pyrochlore phase. This pressure-induced structure transition is mainly controlled by cationic order-disorder modification, and the cationic radius ratio r _A/r

SUBMITTER: Niu J 

PROVIDER: S-EPMC6774973 | biostudies-literature | 2019 Sep

REPOSITORIES: biostudies-literature