Synthesis and luminescence characterization of Y2 BaZnO5 :RE (RE = Eu3+ , Tb3+ , Pr3+ and Sm3+ ) phosphors.

ABSTRACT

Modified synthesis and luminescence of Y2 BaZnO5 phosphors activated with the rare earths (RE) Eu3+ , Tb3+ , Pr3+ and Sm3+ are reported. RE2 BaZnO5 phosphors have attracted attention because of their interesting magnetic and optical properties; and are usually prepared using a two-step solid-state reaction. In the first step, carbonates or similar precursors are thoroughly mixed and heated at 900°C to decompose them to oxides. To eliminate the unwanted phases like BaRE2 O4 , the resulting powders are reheated at 1100°C for a long time. We prepared Y2 BaZnO5 phosphors activated with various activators by replacing the first step with combustion synthesis. The photoluminescence results are presented. The photoluminescence results for Eu3+ , Tb3+ and Pr3+ are in good agreement with the literature. However, photoluminescence emission from Sm3+ has not been documented previously. The excitation spectrum of Eu3+ is dominated by a charge transfer band around 261 nm, and an additional band around 238 nm is always present, irrespective of the type of activator. The presence of this band for all these different types of activators was interpreted as host absorption.