Synthesis of Europium (II) Doped Calcium Carbonate Phosphor under Coexisting Ammonium Chloride and Its Fluorescence Property

Abstract

This paper reports about synthesis and fluorescence properties of Eu (II) doped vaterite phosphor emitting blue color by black light irradiation. Eu (III) doped vaterite phosphor was synthesized by a liquid phase reaction by adding 0.1 mol·dm-3 (NH4)2CO3 solution into 0.10 mol·dm-3 CaCl2 solution including EuCl3 at 35°C. On the other hand, Eu2+ doped vaterite phosphor formed by heating mixture of Eu3+ doped vaterite and NH4Cl. The upper limit of the incorporation of Eu3+ ion in vaterite structure was Eu/Ca atomic ratio of 0.01. Eu2+ doped vaterite phosphor could be also obtained by reduction of Eu3+ doped vaterite phosphor using NH4Cl. Optimum synthetic conditions for Eu2+ doped vaterite phosphor with Eu/Ca atomic ratio 0.01 were: heating temperature of 350°C, time of 50 min and amount of NH4Cl of 10 mass%. Emission wavelength of Eu2+ doped vaterite phosphor excited with 339 nm light was observed at about 427 nm and the emitted color was blue.