Effect of cobalt doping on the structural, magnetic and abnormal thermal expansion properties of NaZn13-type La(Fe1−xCox)11.4Al1.6 compounds

Abstract

Cubic NaZn₁₃-type La(Fe_1−xCo_x)_11.4Al_1.6 compounds were synthesized and extensively explored through crystal structure and magnetization analyses. By optimizing the chemical composition, the isotropic abnormal properties of excellent zero and giant negative thermal expansion in a pure form were both found at different temperature ranges through room temperature. Moreover, the temperature regions with the remarkable abnormal thermal expansion (ATE) properties have been broadened which are controlled by the dM/dT. The present study demonstrates that the ATE behavior mainly depends on special structural and magnetic properties. These diverse properties suggest the high potential of La(Fe_1−xCo_x)_11.4Al_1.6 for the development of abnormal expansion materials.