Synthesis, Crystal Structure, and Physical Properties of Layered Ln CrSe2O (Ln = Ce-Nd)

Xian Zhang; Yi Xiao; Ruiqi Wang; Jianqiao He; Dong Wang; Kejun Bu; Gang Mu; Fuqiang Huang

doi:10.1021/acs.inorgchem.9b01364

Synthesis, Crystal Structure, and Physical Properties of Layered Ln CrSe₂O (Ln = Ce-Nd)

Inorg Chem. 2019 Jul 15;58(14):9482-9489. doi: 10.1021/acs.inorgchem.9b01364. Epub 2019 Jun 26.

Authors

Xian Zhang¹, Yi Xiao², Ruiqi Wang², Jianqiao He³, Dong Wang³, Kejun Bu³, Gang Mu⁴, Fuqiang Huang^{2

3}

Affiliations

¹ Qian Xuesen Laboratory of Space Technology , China Academy of Space Technology , Beijing 100094 , P. R. China.
² State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering , Peking University , Beijing 100871 , P. R. China.
³ CAS Key Laboratory of Materials for Energy Conversion and State Key Laboratory of High Performance Ceramics and Superfine Microstructure , Shanghai Institute of Ceramics, Chinese Academy of Sciences , Shanghai 200050 , P. R. China.
⁴ State Key Laboratory of Functional Materials for Informatics , Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences , Shanghai , P. R. China.

PMID: 31241920
DOI: 10.1021/acs.inorgchem.9b01364

Abstract

The layered oxyselenides with the formula LnCrSe₂O (Ln = Ce-Nd) were synthesized via molten salt methods. The isostructural compounds crystallize in the monoclinic space group of C2/m. The crystal structures feature _∞²[CrSe₂O]^3- motifs stacked along the a axis, which are separated by Ln³⁺ ions. The _∞²[CrSe₂O]^3- layers are composed of [Cr1Se₆]^9- and [Cr2Se₄O₂]^9- octahedra via corner and edge sharing. Powder X-ray diffraction results confirm the phase purities of the as-synthesized compounds. LnCrSe₂O (Ln = Ce-Nd) show typical antiferromagnetic ordering with T_N = 125, 120, and 118 K, respectively. Heat capacity measurement for NdCrSe₂O indicates that the Debye temperature is 278.4 K. Similar metal-to-semiconductor phase transitions were observed for LnCrSe₂O (Ln = Ce-Nd) plates with transition temperatures of 115, 109, and 95 K, respectively. NdCrSe₂O also possesses a magnetoresistance effect at low temperature (<25 K) with a significant positive magnetoresistance ∼ 16% at 2 K and 1 T.