Devitfrification Properties Of Bismuth Borate Glasses Doped With Trivalent Ions

Bismuth borate glasses and crystalline phases have outstanding luminescent and nonlinear optical properties; therefore there is lot of interest in their preparation and characterization. In this study we report the crystallization properties of bismuth borate glasses doped with trivalent ions. Glasses of the composition: xBi(2)O(3)-(100-x)B2O3 (x=20, 25, 30, 37.5, 40, 50, 60 and 66 mol %) and 40Bi(2)O(3)-1Tv(2)O(3)-59B(2)O(3) (where Tv=Al, Nd and Eu) were prepared by melt quench technique and devitrified by heat treatment above their glass transition temperatures for several hours. The crystalline phases produced were characterized by FTER absorption spectroscopy, DTA and X-ray diffraction. Bi3B5O12 was found to be the predominant phase in all crystallized samples containing Bi2O3 concentration of <= 40 mol %, at higher Bi2O3 concentration, we observed the formation of Bi4B2O9 phase. Glasses with Bi2O3 concentration of <= 37.5 mol % produced Bi2B8O15 phase on crystallization. The metastable BiBO3-I phase was formed by short duration heat treatment (less than 5 hours) of the initial glass sample. Doping with rare earth ions like Eu3+ and Nd3+ promotes the formation of BiBO3-II phase while Al3+ doping suppresses it.