Magnetic Ordering and Structural Transition in the Ordered Double-Perovskite Pb2NiMoO6

Jianfa Zhao, Xiao Wang, Xi Shen, Christoph J. Sahle, Cheng Dong, Hajime Hojo, Yuki Sakai, Jun Zhang, Wenmin Li, Lei Duan, Ting Shan Chan, Chien Te Chen, Johannes Falke, Cheng En Liu, Chang Yang Kuo, Zheng Deng, Xiancheng Wang, Richeng Yu, Runze Yu*, Zhiwei Hu*Martha Greenblatt, Changqing Jin*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

4 Scopus citations

Abstract

The B-site-ordered double-perovskite Pb2NiMoO6 was prepared at high pressure and high temperature. The structural analysis of synchrotron powder X-ray diffraction data shows that Pb2NiMoO6 crystallizes into monoclinic symmetry with the space group Pc (no. 7), where the Ni and Mo ions are ordered in a rock-salt-type manner. The magnetic and specific heat characterizations reveal unusual two-step antiferromagnetic (AFM) transitions at 18 and 26 K for Pb2NiMoO6. The X-ray absorption spectra at the Ni-L2,3 edge and the Mo-L3 edge and the high-resolution partial fluorescence yield at the Pb-L3 edge indicate Pb2+2Ni2+Mo6+O6 valence states. Although in A2NiMoO6 (A = Sr2+, Pb2+, and Ba2+), the size of the A cation increases gradually from Sr2+ (1.44 Å) to Pb2+ (1.49 Å) to Ba2+ (1.61 Å), Pb2NiMoO6 exhibits much lower symmetry structure and AFM transition temperature, TN, compared with Sr2NiMoO6 (I4/m, TN = 81 K) and Ba2NiMoO6 (Fm3¯ m, TN = 64 K), which is attributed to the large distortion of NiO6 and MoO6 octahedra induced by the lone pair electron effect of Pb2+ with a 6s2 electronic configuration. Moreover, symmetry-breaking phase transition from a high-temperature centrosymmetric, cubic Fm3¯ m phase to a low-temperature non-centrosymmetric, monoclinic Pc phase was observed at 393-413 K in Pb2NiMoO6.

Original languageEnglish
Pages (from-to)97-106
Number of pages10
JournalChemistry of Materials
Volume34
Issue number1
DOIs
StatePublished - 11 Jan 2022

Fingerprint

Dive into the research topics of 'Magnetic Ordering and Structural Transition in the Ordered Double-Perovskite Pb2NiMoO6'. Together they form a unique fingerprint.

Cite this