Terahertz-infrared spectra of the rare-earth scandate DyScO_3 single crystal

摘要

Terahertz and infrared spectra of the optical response of DyScO_3 single crystal are measured at temperatures from 5 K to 300K for two different polarizations E‖[101] and E‖[010], i.e., along the two crystallographic directions of the DyScO_3 substrates used for growing of thin films and heterostructures. Detailed reference data on the terahertz dielectric characteristics of the DyScO_3 substrate are presented. We discuss the mechanisms responsible for electromagnetic absorption. Phonon spectra are analyzed along with the results of group-theoretical analysis of the crystal structure. Besides phonon modes, additional resonance absorptions are found and assigned to the electronic transitions between Kramers doublets in the three lowest-energy terms of the Dy~(3+) ion.