Effect of H2O Molecules on Thermal Expansion of TiCo(CN)6

Published

October 19, 2020

Author(s)

Qilong Gao, Xinwei Shi, Alessandro Venier, Qingzhen Huang, Hui Wu, Jun Chen, Andrea Sanson, Erjun Liang

Abstract

The understanding of the role of guest molecules in the lattice void of open-framework structures is vital for thermal expansion tailoring. Here, we take a new NTE compound, TiCo(CN)₆ as a case study from the local structure perspective to investigate the effect of H₂O molecules on the thermal expansion. The in-situ SXRD re-sults showed that the as-prepared TiCo(CN)₆⋅2H₂O has near zero thermal expansion behavior (100-300 K) while TiCo(CN)₆ without water in the lattice void exhibits a linear NTE (α_l=-4.05×10^-6K^-1, 100-475 K). Combined with the results of extended X-ray absorption fine structure, it is found that the intercalation of H₂O molecules has the clear effect of inhibiting the transverse thermal vibrations of Ti-N bonds, while the effect on Co-C bonds is negligible. The present work displays the inhibition mechanism of H₂O molecules in the thermal expansion of TiCo(CN)₆, which also provides insight in the thermal expansion control of other NTE compounds with open-framework structures.

Citation

Inorganic Chemistry

Volume

59

Issue

20

Pub Type

Journals

Keywords

Thermal expansion, diffraction, negative thermal expansion

Citation

Gao, Q. , Shi, X. , Venier, A. , Huang, Q. , Wu, H. , Chen, J. , Sanson, A. and Liang, E. (2020), Effect of H₂O Molecules on Thermal Expansion of TiCo(CN)₆, Inorganic Chemistry (Accessed October 6, 2024)