High-Pressure Synthesis of the Cobalt Pyrochlore Oxide Pb2Co2O7 with Large Cation Mixed Occupancy

Junye Yang, Jianhong Dai, Zhehong Liu, Runze Yu, Hajime Hojo, Zhiwei Hu, Tunwen Pi, Yunliang Soo, Changqing Jin, Masaki Azuma, Youwen Long

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

The novel A2B2O7-type compound Pb2Co2O7 was synthesized at 8 GPa and 1673 K. Synchrotron X-ray diffraction shows a cubic pyrochlore structure with space group Fd3m. Rietveld structural analysis reveals a large cation mixed occupancy at both A and B sites by about 40%, the greatest value found in the pyrochlore family. In combination with the X-ray absorption spectroscopy results, the specific chemical composition and charge states are determined to be (Co0.6Pb0.4)3+2(Pb0.6Co0.4)4+2O7, in which both the A-site Co3+ and the B-site Co4+ are low-spin. Due to the tetrahedral geometric frustration effects as well as the random Co4+ and Pb4+ distribution at the B site, spin glassy behavior is well observed following the conventional critical slowing down feature in Pb2Co2O7.

Original languageEnglish
Pages (from-to)11676-11680
Number of pages5
JournalInorganic chemistry
Volume56
Issue number19
DOIs
Publication statusPublished - Oct 2 2017

    Fingerprint

All Science Journal Classification (ASJC) codes

  • Physical and Theoretical Chemistry
  • Inorganic Chemistry

Cite this