Synthesis of fluorozirconate ZBNL glass with partial or complete substitution of europium difluoride for barium (lanthanum) fluorides

The vitrification in two sets of fluorozirconate glass 53.5ZrF 4 · 20NaF · 20BaF 2 · (6.5 − x )LaF 3 · x EuF 2 (0 ≤ x ≤ 6.5 mol %) (I) and 53.5ZrF 4 · 20NaF · (20 − x )BaF 2 · 6.5LaF 3 · x EuF 2 (0 ≤ x ≤ 20 mol %) (II) has been studied. It has been determined that, in set I, at full or partial replacement of lanthanum fluoride by europium difluoride (1–6.5 mol %), colorless transparent glass is formed. In the samples of set II, at the substitution of BaF 2 in order to obtain stable glass under analogous conditions, the initial batch should not contain more than 7.0 mol % EuF 2 . The methods of differential-thermal and X-ray phase analyses and IR and electron spectroscopy were used to study the properties and phase composition of the obtained glass and vitrocrystalline materials. Using the Grubi criterion, the optimal, with respect to crystallization, EuF 2 content has been deter-mined in the glass of both systems. In the devitrified glass of series II, the low-temperature modification of compound EuZrF 6 is formed, in addition to sodium, barium, and lanthanum fluorozirconates. For the vitro-crystalline samples, the absorption bands of Eu-F bonds are observed in infrared spectra, in addition to the broad band (∼500 cm −1 ), which is intrinsic for all fluorozirconate glass. The electron diffuse reflection spectra confirm the presence of both double and triple-charged europium ions in glass.