Design of negative/nearly zero thermal expansion behavior over a wide temperature range by multi-phase composite

Highlights: • A novel method is proposed to design multi-phase composite with NTE/NZTE behavior in a broadened temperature range. • The feasibility of the broadening effect for the proposed method is verified by multi-phase composites experimentally. • Multi-phase composite designed by the proposed method shows excellent stability in thermal expansion properties. • The proposed method may open an avenue to the multi-phase composite with designable thermal expansion properties. The negative thermal expansion (NTE) or nearly zero thermal expansion (NZTE) behaviors have been found in some magnetic metallic compounds with great application prospects. However, it is a big challenge for applications that the responding temperature range is not broad enough or far away from room temperature. Herein, a new method is put forward to design the wide temperature range of NTE and NZTE Behavior by NTE/NZTE multi-phase composite. In this method, the optimized volume fraction of the components achieves a concordant collaboration of multi-phase in the counteraction of NTE and positive thermal expansion (PTE) at several adjacent temperature ranges and thus the temperature range is broadened as expected. By this method, MnCuGeN-based NTE composite (290 K ≤ T ≤ 385 K, ΔT = 95 K) and MnCuZnSiGeN-based NZTE composite (200 K ≤ T ≤ 400 K, ΔT = 200 K) with excellent stability have been successfully designed and prepared. This idea will open an avenue to the multi-phase composite with designable NTE/NZTE properties, which would have important applications in aerospace and other modern industries.