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.