Structural and luminescence responses of CaMoO4 nano phosphors synthesized by hydrothermal route to swift heavy ion irradiation: Elemental and spectral stability

Abstract

The present paper reports on the swift heavy ion (SHI) induced modifications in the structural, optical and luminescence properties of Dy3+ doped CaMoO4 phosphors synthesized via hydrothermal route. The material is irradiated by 30 MeV Li3+, 75 MeV C6+ and 100 MeV Ag7+ ions in the fluence range varying from 1 × 1011 to 1 × 1013 ion/cm2. The ion induced modified properties were investigated by using X-ray diffractometer (XRD), Field Emission Scanning Electron microscopy (FESEM) with energy dispersive x-ray spectroscopy (EDS), X-Ray photoelectron spectroscopy (XPS), diffuse reflectance (DR) and photoluminescence (PL) spectroscopy. The XRD and the FESEM results confirm the loss of crystallinity and reduction of the particle size after SHI irradiations. The change in elemental behavior before and after SHI irradiation is described via EDS assisted elemental mapping and XPS spectroscopy. DR spectra exhibit a red shift in the absorption band, resulting in a decrease in the band gap after ion irradiation. The change in the intensity of the PL peaks without any change in the band positions was noticed after ion irradiation. The variation in structural and optical properties and colour characteristics with ion fluence is discussed in details on the basis of the variation of defect concentration, elemental behavior and the linear energy transfer with ion irradiation.