Irradiation-induced reduction and luminescence properties of Sm2+ doped in BaBPO5

Usually, Sm2+ ions could be reduced by heating the materials in reducing atmospheres. Exposure to ionizing radiations is also known to cause Sm3+→Sm2+ conversion. In this work, BaBPO5 doped with the samarium ion was prepared by high temperature solid-state reaction. Sm2+ ions were obtained by two different reduction methods, i.e., heating in H2 reduced atmosphere and X-ray irradiation. The measurements of X-ray diffraction (XRD), and scanning electron microscope (SEM) were investigated. It is found that the conversion of Sm3+→Sm2+ is very efficient in BaBPO5 hosts after X-ray irradiation. Sm2+ ions under these two reduction methods exhibit different characteristics that were studied by measurements of luminescence and decay. The results showed that the luminescence properties of Sm2+ ions in BaBPO5 were highly dependent on the sample preparation conditions.

The Sm doped in BaBPO5 as-prepared in air contains only Sm3+ ions and shows its fluorescence bands due to the 4G5/2 to 6H5/2, 6H7/2, 6H9/2, and 6H11/2 transitions (a) under the excitation of 488 nm Ar+-ion laser. The emission spectra of the samples after X-ray subsequentially irradiations are characteristic of Sm2+ transitions between the energy levels of 4f6 electronic configurations (b). It is found that the conversion of Sm3+→Sm2+ is very efficient in BaBPO5 hosts after X-ray irradiation.Figure optionsDownload as PowerPoint slide