Recently, La(Fe,Si)₁₃-based compounds have attracted much attention due to their isotropic and tunable abnormal thermal expansion (ATE) properties as well as bright prospects for practical applications. In this research, we have prepared cubic NaZn₁₃-type carbon-doped La(Fe,Si)₁₃ compounds by the arc-melting method, and their ATE and magnetic properties were investigated by means of variable-temperature X-ray diffraction, strain gauge and the physical property measurement system (PPMS). The experimental results indicate that both micro and macro negative thermal expansion (NTE) behaviors gradually weaken with the increase of interstitial carbon atoms. Moreover, the temperature region with the most remarkable NTE properties has been broadened and near zero thermal expansion (NZTE) behavior occurs in the bulk carbon-doped La(Fe,Si)₁₃ compounds.

Phys. Chem. Chem. Phys., 2015

The 12 interstitial sites of the cubic NaZn₁₃-type structure (space group Fm3c) for the LaFe_11.5Si_1.5 compound that the carbon atoms can occupy. (Note: the 12 crystal sites are partially occupied due to inadequate doped carbon atoms in our study).