TY - JOUR
T1 - Magnetic Ordering and Structural Transition in the Ordered Double-Perovskite Pb2NiMoO6
AU - Zhao, Jianfa
AU - Wang, Xiao
AU - Shen, Xi
AU - Sahle, Christoph J.
AU - Dong, Cheng
AU - Hojo, Hajime
AU - Sakai, Yuki
AU - Zhang, Jun
AU - Li, Wenmin
AU - Duan, Lei
AU - Chan, Ting Shan
AU - Chen, Chien Te
AU - Falke, Johannes
AU - Liu, Cheng En
AU - Kuo, Chang Yang
AU - Deng, Zheng
AU - Wang, Xiancheng
AU - Yu, Richeng
AU - Yu, Runze
AU - Hu, Zhiwei
AU - Greenblatt, Martha
AU - Jin, Changqing
N1 - Publisher Copyright:
© 2021 American Chemical Society.
PY - 2022/1/11
Y1 - 2022/1/11
N2 - 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.
AB - 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.
UR - http://www.scopus.com/inward/record.url?scp=85121999856&partnerID=8YFLogxK
U2 - 10.1021/acs.chemmater.1c02826
DO - 10.1021/acs.chemmater.1c02826
M3 - Article
AN - SCOPUS:85121999856
SN - 0897-4756
VL - 34
SP - 97
EP - 106
JO - Chemistry of Materials
JF - Chemistry of Materials
IS - 1
ER -