Structural and optical properties of beta irradiated YAlO3 single crystals

TL;DR

This study investigates the structural, optical, and thermoluminescent properties of YAlO3 single crystals grown by the optical floating zone method, focusing on effects of beta irradiation and impurity influences.

Contribution

It provides new insights into how beta irradiation affects the structural defects, optical emissions, and thermoluminescence behavior of YAlO3 crystals.

Findings

Beta irradiation increases Raman band intensity and line-width, indicating defect formation.

Crystals exhibit a linear dose response in thermoluminescence from 0.1 to 10 Gy.

Presence of Sm and Cr impurities influences optical emission characteristics.

Abstract

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.