The temperature regions of NTE can be tailored by varying the sintering temperature. • Δ T is much larger than that of other Mn 3 CuN-based material by solid-state reaction. • This material with ZTE behavior is desirable for cryogenic application. Abstract Antiperovskite manganese nitride Mn 3 Cu 0.6 Ge 0.4 N was fabricated by spark plasma sintering (SPS) at different temperatures and its negative thermal expansion behavior was investigated. It is observed that the width of negative thermal expansion (NTE) operation-temperature window becomes broader when the sintering temperature decreases. Moreover, it is significantly larger than that of other Mn 3 CuN-based antiperovskite manganese nitrides prepared by solid-state reaction. More interestingly, the Mn 3 Cu 0.6 Ge 0.4 N sintered at 650°C shows near zero thermal expansion (ZTE) behavior in the temperature range of 220–170K. The average linear coefficient of thermal expansion (CTE) is estimated to be −0.9×10 − 6 K − 1 . Magnetic measurement shows that the process of the magnetic transition becomes slow when the sintering temperature decreases. This antiperovskite manganese nitride Mn 3 Cu 0.6 Ge 0.4 N with ZTE behavior is much useful for applications in the fields of cryogenics and applied superconductivity.
Cryogenics, 2014
