Structural and optical properties of silver and titanium nanoparticles co-embedded magnesium-zinc-sulfophosphate glass with neodymium doping

Abstract

Demand of high emission cross-section laser amplifier is ever-increasing. The rare earth ions (REIs) doped magnesium zinc sulfophosphate (PMZ) glasses with noble metal nanoparticles (NPs) inclusion were shown potential as laser host. This study reported that the emission/absorption traits of these REIs inside the glass matrix could be improved using the NPs which enabled localized surface plasmon resonance (LSPR). The LSPR produces strong local electric field (LEF) in the vicinity of the REIs. The melt-quenching method was used to synthesize glass composition 58.5P2O5-20.0MgO-20.0ZnSO4-1.5 Nd2O3-yAg NPs-zTi NPs mol% where y and z could be in the range of 0.0-1.5 mol%. The co-embedment of two types of metal NPs inside the glass could provide flexibility to customize the generated LEF strength in the proximity of the REIs. The X-ray diffraction (XRD) analyses confirmed the amorphous nature of the as-quenched samples. The high-resolution transmission electron microscopy (HRTEM) images showed the nucleation of both Ag and Ti3O5 NPs inside the glass matrix. The nucleation of Ti into Ti3O5 NPs occurred via two-step Finke-Watzky mechanism. Both the Fourier transform infrared (FTIR) and Raman spectral analyses confirmed an insignificant structural change from the incorporation of the NPs into the glass matrix. The observed LSPR band of the Ag (?442 nm) and Ti3O5 (?588 and 774 nm) NPs verified their successful embedment into the host matrix. The ultraviolet-visible-near infrared (UV-Vis-NIR) absorption spectra of the glasses exhibited twelve characteristic absorption bands of Nd3+. The photoluminescence (PL) emission spectra of the prepared glasses disclosed a prominent yellow band around 585 nm, corresponding to the transition of 2G7/2+4G5/2?4I9/2 in Nd3+. The coupling of Ag and Ti NPs into the glass at a certain concentration could lead to PL intensity quenching. This ascribed to the local heating effect of Ti3O5 NPs. The Judd-Ofelt intensity and radiative parameters were calculated from the absorption and PL spectral data. The PMZ1.5Nd04Ti0.3Ag glass sample showed the highest stimulated emission cross-section of 4.78×10–24 cm2. The results suggested that the co-embedment of metal NPs into glass could be an innovative strategy to tailor the spectroscopic characteristics of the glasses which is potential for photonic and solid-state laser applications.