Negative Thermal Expansion of the Dy_2Fe_16Cr Compound

Structural, thermal expansion, and magnetic properties of the Dy_2Fe_16Cr compound are investigated by means of x-ray diffraction and magnetization measurements. The Dy_2Fe_16Cr compound has a hexagonal Th_2Ni_17-type structure. There exists a negative thermal expansion resulting from a strong spontaneous magnetostriction in the magnetic state of the Dy_2Fe_16Cr compound. The average thermal expansion coefficient is -0.794\times 10^-5/K in the temperature range 292–407 K. The spontaneous magnetostrictive deformation and the Curie temperature are discussed.