Structural, optical and luminescence properties of lithium sodium borate glass doped with erbium of neodymium oxide

Abstract

In this study, the structural, optical and thermoluminescence (TL) properties of lithium sodium borate (LNB) glass doped with Er3+ or Nd3+ ions were investigated. The glass dosimeters were prepared by using melt-quenching technique. The X – ray Diffraction (XRD) spectra had confirmed the amorphous nature of the glass samples. The absorption spectra of Er3+ ion doped LNB (LNB:Er) and Nd3+ ion doped LNB (LNB:Nd) glasses revealed hypersensitive transitions at (4I15/2?2H11/2) and (4I9/2 ? 4G5/2 + 2G7/2), respectively. Emission spectra of LNB glasses doped Er3+ ions had shown three violet bands centered at 369 nm (4G11/2?4I15/2), 396 nm (2P3/2?4I13/2) and 423 nm (2H9/2?4I15/2) and a blue band at 477 nm (2P3/2?4I11/2). Meanwhile, LNB glasses doped with Nd3+ ions had exhibited three prominent peaks of photoluminescence spectra which are green, orange and red bands centered at 538 nm (4G7/2 ? 4I9/2), 603 nm [4G7/2 ? 4I11/2, 4G5/2 ? 4I9/2] and 675 nm [4G7/2 ? 4I13/2, 4G5/2 ? 4I11/2], respectively. The introduction of rare earth ions into the glass system had led to the formation of glow curve with prominent peaks at 180 and 220 °C for LNB:Er and LNB:Nd, respectively. The optimum TL intensity of the prepared glasses was determined at 0.3 mol % of Er2O3 and 0.5 mol % of Nd2O3. A good linearity of the TL response against dose was achieved between 0.5 to 4.0 Gy. The sensitivity of 0.3 mol % of Er2O3 glass dosimeter was two times higher than the sensitivity of 0.5 mol % of Nd2O3. The calculated values of the effective atomic number (Zeff) for both compositions were 7.55 which is close to that of the human soft tissue (Zeff = 7.42). These promising features had demonstrated the potential of the studied glasses to be used as radiation.