Giant negative thermal expansion in Ge-doped anti-perovskite manganese nitrides

• DOI: 10.1063/1.2147726
• Publication Date: 2005-12-21T15:49:00Z
• Authors: K. Takenaka; H. Takagi
• Keywords: Negative Thermal Expansion; Lattice (music)

We report the discovery of a large negative thermal expansion (NTE) up to α=−25×10−6K−1 (α: coefficient linear expansion) in Ge-doped anti-perovskite manganese nitrides Mn3AN (A=Cu,Zn,Ga). This gigantic NTE is several ten times higher than that commercially available materials. The discontinuous lattice seen pure broadened by Ge substitution over wide temperature window, at widest ΔT∼100K, around room temperature. Such large, isotropic and nonhysteretic desirable for practical applications.