Lanthanide effect on the formation and evolution of nanocrystalline structures in Ln(2)Hf(2)O(7) compounds (Ln = Sm-Dy)

作者:Popov V V*; Zubavichus Ya V; Menushenkov A P; Yaroslavtsev A A; Kulik E S; Pisarev A A; Kolyshkin N A
来源:Russian Journal of Inorganic Chemistry, 2015, 60(1): 16-22.
DOI:10.1134/S003602361501009X

摘要

X-ray diffraction with synchrotron radiation has been used for comparative analysis of crystal structure evolution in Ln(2)Hf(2)O(7) (Ln = Sm-Dy) complex oxides with a fluorite-pyrochlore structure, synthesized by isothermal annealing of mixed hydroxides. It has been shown that heat treatment of the precursor in the temperature range 600-700A degrees C initiates the formation of nanocrystallites with a fluorite structure. Long-range cationic ordering of the pyrochlore type appears in Ln(2)Hf(2)O(7) (Ln = Sm-Tb) samples once a definite crystal size has been achieved at temperatures a parts per thousand yen1200A degrees C. In Dy2Hf2O7 samples, a defect fluorite structure persists in the entire range of heat-treatment temperatures.

  • 出版日期2015-1