Decreasing crystallite size will broad NTE operation temperature window (Δ T ). • Δ T is much larger than that of other Mn 3 ZnN-based material by solid-state reaction. • This material with large Δ T around room temperature is more useful for applications. Abstract Anti-perovskite manganese nitrides Mn 3 Zn 0.6 Ge 0.4 N with different crystallite size were prepared by spark plasma sintering (SPS) at different sintering temperatures. Their negative thermal expansion (NTE) properties were investigated. It was found that the width of NTE operation-temperature window (Δ T ) broadens with decreasing crystallite size. Typically, a broad Δ T of 105K was obtained in the compound Mn 3 Zn 0.6 Ge 0.4 N with average crystallite size of 54nm sintered at 700°C, of which the average linear thermal expansion coefficient was estimated to be −13.5×10 −6 K −1 in the NTE operation-temperature window. This antiperovskite manganese nitride Mn 3 Zn 0.6 Ge 0.4 N with broadened Δ T around room temperature is more useful for practical applications. Journal of Alloys and Compounds, 2014, Vol.593 |
