The structural properties of CdO–Bi 2 O 3 borophosphate glass system containing Fe 2 O 3 and its role in attenuating neutrons and gamma rays H.A. Saudi a,n , A.G. Mostafa b , N. Sheta a , S.U. El Kameesy c , H.A. Sallam a a Department of Physics, Faculty of Science, Al-Azhar University, Women Branch, Nasr City, Cairo, Egypt b Department of Physics, Faculty of Science, Al-Azhar University, Nasr City, Cairo, Egypt c Department of Physics, Faculty of Science, Ain Shams University, Cairo, Egypt article info Article history: Received 27 May 2011 Accepted 14 June 2011 Available online 24 June 2011 Keywords: Phosphate glasses FTIR measurements Radiation shielding abstract A glass system with chemical formula xBi 2 O 3 –(30  x)CdO–10B 2 O 3 –20Fe 2 O 3 –40P 2 O 5 (0 rx r30) wt% is prepared to be used as radiation shield. The mass attenuation coefficient and half value layer of the glass system to gamma rays have been measured experimentally and compared with those determined from theoretical calculations using the mixture rule of WinXCom program. A database of effective mass removal cross-sections for fast neutrons is also introduced in this work. The obtained results of this study are correlated to the structural properties of these glasses obtained from their IR spectra and the influence of gamma and neutrons irradiation on these structural properties. & 2011 Elsevier B.V. All rights reserved. 1. Introduction Phosphate glasses are technologically important materials because they generally have high thermal expansion coefficients, low transition temperatures and low preparation temperatures [1,2]. These properties have made them ideal materials for funda- mental studies. However, their poor chemical durability limits their diverse uses. Addition of different types of metal oxides like Fe 2 O 3 , to binary phosphate glasses [3,4] has been found to improve the chemical durability and the attenuation of fast neutron [5]. The high chemical durability, high thermal stability and low melting temperatures, which are available for ternary P 2 O 5 –Fe 2 O 3 –R x O y systems, are also achievable for P 2 O 5 –B 2 O 3 –Fe 2 O 3 glasses [6,7]. The physical properties and chemical durability of phosphate glasses can be improved highly by adding different metal oxides of high valance cations such as Bi 3 þ as this oxide forms relatively stable Bi 3 þ –O–P cross-linked bonds [8]. It has been reported that Bi 2 O 3 occupies both network-forming and network-modifying positions in oxide glasses. Therefore, the physical properties of the glasses containing Bi 2 O 3 exhibit discontinuous changes when the struc- tural role of the cation switches over in this way [9] as can be observed also from excellent infrared transmission [12]. The main purpose of this work is the use of infrared spectra to illustrate the change in the structure of the glass system xBi 2 O 3 – (30  x)CdO–10B 2 O 3 –20Fe 2 O 3 –40P 2 O 5 wt%, when interchanging Bi 2 O 3 with CdO, as well as the response of the glasses, towards gamma and neutron irradiation to learn about the suitability of such glasses as radiation-shielding materials. The combination of bismuth and cadmium are used to obtain a maximum density for g ray shielding and retaining an adequate amount of boron–cadmium for neutron shielding, so proving that the glass, which contains Bi 2 O 3 is of better quality than the glass system that contains toxic lead in terms of radiation shielding (gamma rays and neutrons) and environmental hazard [13, 14]. This is accom- plished by determining the shielding properties of the new proposed glass system xBi 2 O 3 –(30  x)CdO–10B 2 O 3 –20Fe 2 O 3 –40P 2 O 5 wt% by measuring the values of the mass attenuation coefficient and the half value layer and compare them with the calculated values that are obtained using the WinXCom program based on the mixture rule, where the mixture rule gives the attenuation coefficient of any substance as the sum of the weighted contributions from the individual atoms in the mixture [15], and also by the development of accurate data base for effective fast neutron removal cross-section of different elements, compounds and substances. For simplicity, fast neutron removal cross-section, S R (cm 1 ), is the probability that a fast or fission-energy neutron undergoes a first collision, which removes it from the group of penetrating and uncollided neutrons. The removal cross-section S R of a given material behaves formally as a cross-section in determining neutron attenuation. The last objective is to correlate between the structural properties and the attenuation behaviors of these glasses. 2. Experimental work Analytically, pure grade chemicals were used to prepare the following glass samples according to the formula: xBi 2 O 3 – (30  x)CdO–10B 2 O 3 –20Fe 2 O 3 –40P 2 O 5 wt% where x ¼ 0, 5, 10, 15, 20, 25 and 30. The batch mixtures were melted in porcelain Contents lists available at ScienceDirect journal homepage: www.elsevier.com/locate/physb Physica B 0921-4526/$ - see front matter & 2011 Elsevier B.V. All rights reserved. doi:10.1016/j.physb.2011.06.038 n Corresponding author. E-mail address: heba_saudi@yahoo.com (H.A. Saudi). Physica B 406 (2011) 4001–4006