Physical, optical, structural and gamma-ray shielding properties of lead sodium borate glasses P. Limkitjaroenporn a,n , J. Kaewkhao b,c , P. Limsuwan a,c , W. Chewpraditkul a a Department of Physics, Faculty of Science King Mongkut’s University of Technology Thonburi, Bangkok 10140, Thailand b Center of Excellence in Glass Technology and Materials Science (CEGM), Nakhon Pathom Rajabhat University, Nakorn Pathom 73000, Thailand c Thailand Center of Excellence in Physics, CHE, Ministry of Education, Bangkok 10400, Thailand article info Article history: Received 6 August 2010 Received in revised form 8 December 2010 Accepted 13 January 2011 Available online 20 January 2011 Keyword: D. Optical properties abstract Lead sodium borate glasses with compositions xPbO:20Na 2 O:(80 x)B 2 O 3 (where x ¼5, 10, 15, 20, 25, 30, 35, 40, 45, 50 and 55 mol%) have been prepared using melt-quenching method and investigated on their optical, physical, structural and gamma-rays shielding properties. The densities of these glass samples were increased with increase in PbO concentration. The FTIR spectra and molar volumes indicate that PbO acts differently on this glass structures over their compositions. For the PbO composition less than 20 mol%, Pb 2+ is incorporated as network former, while it acts as network modifier for the composition from 20–55 mol%. For gamma-ray shielding properties, parameters such as mass attenuation coefficients, effective atomic number and half value layer were increased with increase in PbO concentration. Our results showed relative difference between theory and experiment of less than 1% between experimental and theoretical values. Moreover half value layers of the glass systems have been compared with some standard radiation shielding materials and they exhibited better shielding properties than barite concrete and ferrite concrete at 15 and 25 mol% of PbO, respectively. Crown Copyright & 2011 Published by Elsevier Ltd. All rights reserved. 1. Introduction During recent years, there has been an increasing interest in synthesis, structure and physical properties of heavy metal oxide (HMO) glasses due to their high refractive index, high infrared transparency, high density, good radiation shielding for g-rays and increased third-order non-linear optical susceptibility [1]. Borate glasses are one of the most popular and excellent glass forming materials. Upon addition of alkali oxides to B 2 O 3 the covalent network of amorphous boron oxide causes considerable changes, resulting in the creation of anionic sites that accommo- date the modifying alkali cations [2]. Lead oxide has been used as a constituent in several borate and phosphate glasses in order to achieve useful physical properties. PbO has many extra-ordinary properties such as high refractive index, large density, high non-linear optical susceptibility and excellent infrared transmission. For example, glasses containing Pb provide low melting glasses, which are suitable for sealing applications. High polarizablity of heavy metal oxide glasses also makes them suitable for their use in optically non-linear devices. Moreover the high density of this glass makes it a candidate for radiation shielding material. Although PbO is not a glass-forming oxide by itself, it can be incorporated in substantial quantities into the other glass-forming oxide systems such as SiO 2 ,B 2 O 3 and P 2 O 5 [3]. Sodium oxide is used to expand the glass-forming region and facilitate ion exchange [4] and provide low melting glass. Hence, the structure of lead sodium borate glasses has attracted exten- sive attention in the past several years because of its technologi- cal and industrial interests in applications such as enamels, photonics, opto-electronic [5] and radiation shielding application. Moreover, PbO can enter the glass network both as a network modifier and also as a network former with a formal oxidation state +2. This role depends on the type of bond between lead and oxide [3,5–9]. In this investigation we report on detailed analysis of optical, physical, structural and gamma-rays shielding properties of lead sodium borate glass. The UV–vis optical spectra are used to optical study. This result use to determine the optical band gap, refractive index and polarizability of glasses. Fourier transform infrared (FTIR) transmission spectra have been measured for obtaining the structural information of these glasses. The present studies attempt to correlate the changes in molar volume as the result of structural changes in the borate network. The optical basicity of glasses is also calculated. Moreover, the gamma-rays shielding properties such as the mass attenuation coefficients, the Contents lists available at ScienceDirect journal homepage: www.elsevier.com/locate/jpcs Journal of Physics and Chemistry of Solids 0022-3697/$ - see front matter Crown Copyright & 2011 Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.jpcs.2011.01.007 n Corresponding author. E-mail address: golfpo@hotmail.com (P. Limkitjaroenporn). Journal of Physics and Chemistry of Solids 72 (2011) 245–251