  We present reflectance measurements in the infrared region on a single
crystal the rare earth scandate DyScO3. Measurements performed between room
temperature and 10 K allow to determine the frequency of the infrared-active
phonons, never investigated experimentally, and to get information on their
temperature dependence. A comparison with the phonon peak frequency resulting
from ab-initio computations is also provided. We finally report detailed data
on the frequency dependence of the complex refractive index of DyScO3 in the
terahertz region, which is important in the analysis of terahertz measurements
on thin films deposited on DyScO3.
