Properties of ultraviolet phosphor for ion-beam-induced fluorescent microscopy technology

In this study, we have investigated the ultraviolet (UV) fluorescence properties of a phosphor (YPO4:Gd) sample from the irradiation of a scanning proton beam to evaluate its usefulness as a staining agent of ion-beam-induced fluorescence microscopy (IBIF). The phosphor was prepared using a co-precipitation method. Owing to the irradiation, the sample exhibited UV fluorescence with a peak wavelength of 312 nm. In the emission spectrum, the FWHM of the UV peak ≈ 6 nm. The light emission in the UV region and the narrow peak bandwidth are characteristics that are effective at minimizing the background fluorescence and allow high-sensitivity IBIF imaging. Moreover, it was confirmed that the phosphor had a considerable radiation endurance. In addition, we successfully obtained IBIF images and elemental maps simultaneously for a test sample containing YPO4:Gd powder. These results demonstrate that the prepared phosphor is suitable for IBIF.