An influence of neodymium (Nd3+) doping on physicochemical properties of monoclinic lanthanum arsenate (LaAsO4) nanomaterials.

This paper reports synthesis by wet chemical route for neodymium doped lanthanum arsenates nanoparticles with chemical formula NdxLa1−xAsO4 (x = 0.0, 0.05, 0.10 and 0.15) and its characterization. Powder X-ray diffraction (PXRD) confirms monoclinic structure of the prepared nanomaterials. Crystallite size decreases with increasing concentration of Nd3+ ions. PXRD results are further validated by Rietveld refinement with low values of goodness factor (χ2). Morphology has been investigated by high resolution transmission electron microscopy (HRTEM) equipped with selected area electron diffraction (SAED) which shows the crystalline nature of nanomaterials. Various functional groups present have been studied by FTIR spectroscopy. The optical band gap calculated using UV–Vis diffuse reflectance spectroscopy is found to decrease with increasing dopant concentration. The emission spectrum studied by applying photoluminescence (PL) spectroscopy. At 315 nm excitation, the NdxLa1−xAsO4 exhibits a bright red emission with emission peaks in the range of 610–630 nm. Chromaticity plot shows that chromaticity coordinates are located in the red region. The dielectric analysis carried out to study variation of dielectric constant with frequency over range of 1–25 kHz and temperature range of 20–200 °C. The conductivity measurements are carried out and activation energy has been calculated. The variation of electrical modulus with frequency has also been observed. [ABSTRACT FROM AUTHOR]