Magnetic properties of DyAsO₄ at low temperatures

Abstract

Abstract The magnetic properties of DyAsO 4 were investigated by specific heat and magnetic moment measurements. The specific heat shows two λ‐type anomalies, one at T N = 2.44 K caused by a magnetic phase transition, and the other at T c = 11.2 K. Magnetic measurements show an antiferromagnetic ordering perpendicular to the optical axis with magnetically nonequivalent a ‐ and a ′‐axes. Exchange integral and critical parameters were determined in different ways and compared with theory. The splitting of the two lowest components (Kramers' doublets) which is constant above T c becomes temperature dependent below T c ; it increases with decreasing temperature and originates from a cooperative phenomenon.