Zero thermal expansion in a pure-form antiperovskite manganese nitride

A zero thermal expansion material in a pure form is fabricated using an antiperovskite manganese nitride. The isotropic zero thermal expansion is achieved by optimizing the heat treatment and the chemical composition. The present study suggests that the heat treatment affects the thermal expansion mainly via the nitrogen content of the material. The obtained materials exhibit a low expansion of |α|<0.5×10−6 K−1 (α is the coefficient of linear thermal expansion) over a broad temperature range, which includes room temperature. They are desirable for many fields of industry as reliable, mechanically hard, and low-cost zero thermal expansion materials.