Abstract:
The novel Cr3+ doped barium-boro-tellurite ternary glasses having compositions xBaO-(30-x) TeO2-69.5B(2)O(3)-0.5Cr(2)O(3) where x = 10, 15, 20 & 25 (BTBCr-1, BTBCr-2, BTBCr-3 & BTBCr-4 respectively) were prepared using high purity raw materials with the melt-quench method. The amorphous structure of the glass samples was confirmed by XRD and SEM examination. The EDS analysis shows that the prepared samples were free from impurities. Other spectroscopic results have been analyzed in the light of different compositions with the help of data on optical absorption and EPR (experimental & theoretical) spectra. From the optical absorption spectra, four bands were observed around 440, 645, 680 and 716 nm and were assigned to the transitions from the ground state (4)A(2 g)(F) to T-4(1 g)(F), T-4(2 g)(F), T-2(1 g)(G) and E-2(g)(G) respectively. Four well distinct EPR signals were observed at g asymptotic to 5.23, g asymptotic to 4.25, g asymptotic to 2.38 and g asymptotic to 1.97. The rhombic symmetry of scattered individual Cr3+ ion sites arises due to the high g -value (g asymptotic to 5.23). The theoretical studies were carried out at g asymptotic to 1.97 resonance signals. The results show that the concentration of Cr3+ ions in the glass matrix varied in a non-linear manner. Furthermore, the photon and fast neutron shielding ability of the glasses were estimated through FLUKA simulations and direct calculations. For photon energies within 0.284-2.51 MeV, the linear attenuation coefficient fluctuates between the range 0.4538-0.1231, 0.4744-0.1277, 0.4936-0.1295, and 0.5137-0.1328 cm(-1 )for BTBCr-1, -2, -3, and -4 respectively. Generally, the increase in the BaO content had a positive influence on the photon and fast neutron shielding efficiency of the glass system. Compared to some common shields, the BTBCr glasses have huge potential as radiation shields.
