Solid State Phenomena Vol. 392

Abstract: The rapid progress of nanotechnology has created new avenues for the development of innovation in medical and biological devices. Transition metal dichalcogenides (TMDs) nanostructures such as tungsten disulfide nanodiscs (WS₂-NDs) decorated with metallic nanoparticles, provide promising novel materials for surface Enhanced Raman Spectroscopy (SERS). This work focuses on the design and fabrication of a new SERS substrate based on AuNPs/WS₂-NDs hybrid system, which exhibits a strong localized surface plasmonic resonance (LSPR) and achieves up to an order of magnitude enhancement in Raman spectra intensity compared to WS₂-NDs only. This superior performance is attributed to the improved electromagnetic mechanism (EM) on the metallic gold nanoparticles and on the nonmetallic TMDs nanostructures. The chemical mechanism (CM), which facilitates charge transfer between analyte molecules and WS₂-NDs, allows for further improvement of Raman spectra on SERS on tungsten disulfide nanodiscs.

Abstract: This study explores the phase and structural transformations of new lanthanum substituted sodium lead phosphate composite, Pb_(8-x)La_xNa₂(PO₄)₆ with x=0.00 to 0.30. The main focus is to establish the limits of substitution of La³⁺ in the apatite lattice and to understand its effect after substitution. The apatite composite specimen was prepared through a solid–state reaction at 830 °C and characterized using Rietveld–XRD, FT IR and SEM techniques. The statistics suggest that the structure mostly remains a constant up to x = 0.20. However, when the amount of lanthanum exceeds the limit, secondary phases exist and become dominant showing the limit of lanthanum entry. The insertion leads to changes in the host-cation lattice; namely a nonlinear variation along the a-axis, while there is a linear variation along the c-axis in lead-apatite. FT-IR data further confirms that PO₄³⁻ is a tetrahedral ion in the structure. Microstructure is more densely packed what is new in this work is the study of the structural changes which lead to the formation of larger amounts of lead-apatite composites with a wider range of La³⁺ range. The structural changes seen in this study shed light on the structural changes that must occur for effective integration of lead-apatite composites. A fresh perspective on how this study contributes to your submission.