Optical and radiospectroscopic studies of antiferroelastic phase transition in KDy (MoO4)2

Abstract The data on low-frequency states were obtained by near ir optic measurements and far ir studies just in the frequency range corresponding to the energy separation between two low-lying levels of the ground term 6H15/2 of the Dy3+ ion. The experiments were performed at magnetic fields up to 70 kOe in the temperature range of 5 to 25 K including the structural phase transition temperature of 14 K. The experimental data are in satisfactory agreement with the calculation made in the crystal field approach for the microscopic model that describes the SPT by the multiplication of the unit cell and the rhombic distortion of quasi-tetragonal centers of Dy3+ ions.