Thermal Expansion of Anti-Perovskite Mn3Zn1-xSnxN Compounds

Abstract

The anti-perovskite structured Mn3XN(X=Cu,Al,Ag,Zn,Ga,Sn,In) have wide perspective and practicability with unique advantages compared with other materials as a new negative thermal expansion (NTE) material. Because of its simple preparation and unique properties of NTE, this kind of compounds aroused scientists’ attention. The metallic nitrides Mn3Zn1-xSnxN (x=0.1, 0.2, 0.3, 0.4, 0.5) were prepared by solid-state sintering. The anti-perovskite compound Mn3Zn1-xSnxN has a cubic crystal structure with space group Pm3m. It shows that Zn element is partial replaced by Sn element. The Sn doping in Mn3Zn1-xSnxN compound can cause the thermal expansion behavior of the compound to change between positive and negative by analyzing the curve of thermal expansivity with the temperature. Mn3Zn0.7Sn0.3N shows a very strong NTE. Its negative thermal expansion coefficients were -4.39×10-4/K from 345.4 °C to 476.2 °C. In addition, the variation of the thermal expansion curve for Mn3Zn0.8Sn0.2N is almost negligible with the increasing of temperature to 600 °C, exhibiting nearly zero thermal expansion behavior. Therefore, the thermal expansion of Mn3Zn1-xSnxN could be tuned via different contents of Sn in Mn3ZnN.