  We report on the growth, structural and optical properties of YAlO3 single
crystals grown by optical floating zone technique. Powder X-ray diffraction and
Raman spectroscopic studies confirm the phase purity of the crystals. Raman
analysis reveals that the intensity and line-width of Raman bands increase
significantly with beta irradiation indicating the formation of structural
defects in YAlO3 lattice. The optical properties are studied through UV-visible
absorption, and photoluminescence emission and excitation spectroscopies under
pre- and post- beta irradiation. The optical studies indicate the presence of
Sm and Cr impurities by exhibiting characteristic emission lines in the orange
red region. Further, a systematic study on the thermoluminescence (TL)
characteristics of the crystal is also carried out at different doses of beta
irradiation. The crystals exhibit a prominent TL glow peak at 239 C for less
than 5 Gy doses while a weak second glow peak evolves at higher doses. Also,
the crystals show a nearly linear dose response in the studied range from 0.1
to 10 Gy. The glow curve analysis reveals that the TL emission obeys the first
order kinetics model. Based on the optical studies, the plausible mechanism for
the TL glow curve is discussed in terms of the intrinsic defects and impurities
that are present in the crystal.
