Structural changes of (K,Gd)(2)Ta(2)O(7) pyrochlore at high pressure
- Univ. of Michigan, Ann Arbor, MI (United States)
- Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
The structure of K-bearing tantalate pyrochlore (K2–xGdx)Ta₂O6+x (x~0.4) was studied at high pressures using in situ X-ray diffraction and Raman scattering methods. Experimental results indicated that (K2–xGdx)Ta₂O6+x (x~0.4) retains the pyrochlore structure up to 40 GPa, but partial amorphization occurred at pressures above 23 GPa. The amorphous phase was also confirmed in the quenched sample by means of transmission electron microscopy. The tantalate pyrochlore lattice is more stable than pyrochlore compounds in other systems, such as rare earth titanates, zirconates and stannates. The structural stability of pyrochlore tantalate may be mainly related to the size ratio of cations on the 16d and 16c sites in the lattice.
- Research Organization:
- Energy Frontier Research Centers (EFRC) (United States). Materials Science of Actinides (MSA)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- SC0001089
- OSTI ID:
- 1065992
- Journal Information:
- Journal of Solid State Chemistry, Vol. 184, Issue 9; Related Information: MSA partners with University of Notre Dame (lead); University of California, Davis; Florida State University; George Washington University; University of Michigan; University of Minnesota; Oak Ridge National Laboratory; Oregon state University; Rensselaer Polytechnic Institute; Savannah River National Laboratory; ISSN 0022-4596
- Publisher:
- Elsevier
- Country of Publication:
- United States
- Language:
- English
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