Investigation of ZnO-P2O5 Glasses Containing Variable Bi2O3 Contents Through Combined Optical, Structural, Crystallization Analysis and Interactions with Gamma Rays

Optical absorption spectra of prepared undoped zinc phosphate glass together with samples containing additional Bi2O3 (2.5, 5, 10, 15%) were measured within the range 200–1100 nm before and after gamma irradiation. The spectrum of the undoped glass reveals strong UV absorption which is related to the presence of trace ferric ions (Fe 3+) present as unaviodable impurities within theraw materials. Bi2O3-containing glasses show an additional broad band near the visible band centered at about 464 nm which is attributed to the absorption of Bi 3+ ions. Gamma irradiation is observed to cause extension of the UV absorption of the undoped and the sample containing low 2.5% Bi2O3. The broad visible band due to Bi 3+ is not affected by gamma irradiation indicating some shielding behavior due to the presence of heavy massive Bi 3+ ions. Infrared absorption spectra of the studied glasses reveal vibrational bands due mainly to metaphosphate groups which show interference with the vibrations due to the introduction of Bi–O bonding groups (as BiO6, BiO3 or P–O–Bi) specially with the increase of Bi2O3. The crystallization behavior is discussed in relation to the phase separation concept and ionic potential of the Zn 2+ ions together with the depolymerization effect of Bi2O3 to convert metaphosphate to pyrophospahte and the formation of a crystalline bismuth phosphate phase.