Magnetovolume effects in manganese nitrides with antiperovskite structure.

Magnetostructural correlations in antiperovskite manganese nitrides were investigated systematically for stoichiometric and solid solution MnCu A N (A = Co, Ni, Zn, Ga, Ge, Rh, Pd, Ag, In, Sn or Sb). This class of nitrides is attracting great attention because of their giant negative thermal expansion, which is achieved by doping Ge or Sn into the A site as a relaxant of the sharp volume contraction on heating (spontaneous volume magnetostriction ) because of the magnetovolume effects. The physical background of large and mechanism of how the volume contraction becomes gradual with temperature are central concerns for the physics and applications of these nitrides.