@bachelorsthesis{1999S,
  title={Far-infrared polarized reflectance measurements of the vacancy-doped perovskite Sm<sub>0.95</sub>TiO<sub>3</sub>},
  author={Aaron D. Slepkov},
  month={May},
  year={1999},
  abstract={A Martin-Puplett far-infrared polarizing interferometer was used to make
polarized reflectance measurements on both the long axis and a short axis of
the distorted orthorhombic vacancy doped perovskite Sm<sub>0.95</sub>TiO<sub3</sub>.
A <sup>3</sup>He refrigerator cryostat was used to make measurements at temperatures varying
from 90 K to 0.6 K. A sapphire-silicon bolometer, operating at 0.4 K, was used as
the detector. The frequency range investigated was 12-250 cm<sup>-1</sup>. Kramers-Kronig
analysis was carried out to determine the optical conductivity from the measured
reflectance. In this range, three interesting regions were observed. A finite
background conductivity is seen at very low frequencies, showing a dc residual
conductivity on the order of 20-30 omega<sup>-1</sup> cm<sup>-1</sup>. A somewhat temperature dependent
feature is observed at 120 cm<sup>-1</sup>. This feature is probably magnetic in origin, as
it is seen to have a clear temperature dependence through the Neel temperature of
stoichiometric Sm<sub>0.95</sub>TiO<sub3</sub>. The third feature observed is an
expected normal phonon mode arising at 170 cm<sup>-1</sup>. This phonon seems to shift to
higher frequencies as the temperature is lowered below the Neel temperature. It
also seems to become less symmetric, although the phonon was not fitted for
oscillator parameters. This behaviour may be attributed to coupling of the
electronic background to the phonon. It may also be a result of coupling of the
phonon to its neighbouring feature at 120 cm<sup>-1</sup>.},
  note={Supervised by M. Reedyk}
}