Negative Thermal Expansion and Spontaneous Magnetostriction of Nd2Fe16.5Cr0.5 Compound*

Abstract

The structural, thermal expansion, and magnetic properties of the Nd2Fe16.5Cr0.5 compound are investigated by means of x-ray diffraction and magnetization measurements. The Nd2Fe16.5Cr0.5 compound has a rhombohedral Th2Zn17-type structure. There exists a small negative thermal expansion resulting from a spontaneous magnetostriction in the magnetic state of the Nd2Fe16.5Cr0.5 compound. The average thermal expansion coefficient is −1.06 × 10−6/K in a temperature range 299–394 K. The spontaneous magnetostrictive deformation and the Curie temperature are discussed.