Rare earth ion Tb3+ doped natural sodium feldspar (NaAlSi3O8) Luminescent properties and energy transfer

Abstract

In this study, Tb³⁺—doped natural sodium feldspar (NaAlSi₃O₈) phosphors have been successfully prepared using high−temperature solid—state method with natural sodium feldspar as a substrate. Energy—dispersive X—ray spectrometry analysis (EDX) of NaAlSi₃O₈ showed that 0.03 wt% of Eu element was present, and elemental distribution mapping analysis showed that the distribution of trace Eu in minerals was aggregated. The crystal structure and luminescence properties of the natural sodium Eu—containing feldspar and synthetic sodium feldspar NaAlSi₃O₈:Eu³⁺, Tb³⁺ phosphors are discussed in detail. The crystal structure analysis of the samples showed that the Na⁺ in the natural matrix was partly replaced by the doped Tb³⁺. Studies on the photoluminescence properties of the samples indicate that Eu does not form a luminescent center in the natural mineral, however, the strong characteristic peak of Eu³⁺ at 615 nm appears after doping with Tb³⁺ and the peak at 615 nm increases with the increase of Tb³⁺ concentration. According to the above spectral results, the energy transfer from Tb³⁺ to Eu³⁺ is obtained. Through the measurement and analysis of color coordinates, it is found that with the increase of Tb³⁺ concentration, the luminescence color of the samples can be regulated in the green to red region. NaAlSi₃O₈:Eu³⁺ Tb³⁺ phosphors has potential application value.