Abstract
Our research was focused on studying the growth and optical characteristics of YbFe2O4
thin films. YbFe2O4 (YbFO) samples were prepared by a solid state reaction. The
stoichiometric proportion of Yb2O3, FeO, and Fe2O3 powders were mixed and ground
using a mortar and pestle, then pressed into pellets of about 3g and 0.5 inch diameter
each using a hydraulic press. The pellets were then sintered in the furnace at 1000 ºC for
12 hours. After sintering, the pellets were ground, pressed and sintered for a second and
sometimes third time. To make the YbFO thin films, we used an electron beam deposition
method. The pellets were placed into crucibles and the target pellet was heated by an
electron beam for about an hour. The YbFO pellet slowly evaporates onto YSZ and
sapphire substrates heated at 850 ºC until the desired thickness was reached. YbFO thin
films were annealed for 3 hours at 600 ºC. Reflectance and transmittance versus
wavelength (200 - 3000 nm) of YbFO thin films were measured at temperatures between
10 K and 400 K using spectrometers. The optical data of YbFO show several electronic
peaks associated with the intra (Fe 3d to d) and inter (O 2p to Fe 3d, Yb 6s, and 5d)
atomic electronic transitions. Moreover, the optical properties change as temperature
changes, suggesting a strong temperature dependence.
