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

Abstract

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.