Crystal Structure of Dysprosium at Low Temperatures

Abstract

The temperature dependence of the lattice parameters of Dy has been studied from room temperature to 30°K. The previously reported expansion along the c axis of the hexagonal close‐packed structure below T_N=179°K has been observed in detail and found to be in agreement with predictions of Kittel. At the first‐order antiferromagnetic‐ferromagnetic transition T_S=86°K a crystal structure distortion to orthorhombic was observed. The ratio of orthorhombic axes changes from b/a=1.732=√3 to 1.720 just below T_S and to 1.715 at 30°K.