In this study, nanostructured Ce- and Sm-substituted Ca10(PO4)6(OH)2 samples have been synthesized using an aqueous sol-gel chemistry route. For the characterization of obtained specimens, the XRD, SEM, UV-visible reflection and IR spectroscopy and luminescence measurements were recorded. It was shown that phase purity of the end products highly depends on the amount of lanthanide element. The reflectance of lanthanide-substituted calcium hydroxyapatite samples is wavelength independent in the wavelength range of 450-800 nm and equal almost 100%. The cerium-substituted samples show a significant decrease of transmission at ~300 nm. The characteristic samarium absorption line (~430 nm) is evident in the UV-vis reflection spectra of samarium-substituted hydroxyapatites.
The effects of partial substitution of La by a smaller Lanthanide element (R) in La 0.7-x R x Ca 0.3 MnO 3 ( R = Ce , Pr, Nd Sm, Gd, Dy with x = 0 and 0.1) ceramic pellets on the electron paramagnetic resonance has been investigated. The line width increased with decrease in ionic radius of the A site <r A > in paramagnetic phase, which is explained on the basis of tolerance factor. The observed increase in g-value and line width with increase in <r A > in ferromagnetic phase explained qualitatively by Mn-O-Mn bond angle distortion and Mn-O orbital overlap which in turn is governed by the size of the substitution ion.
Oxo-Functionalization and Reduction of the Uranyl Ion through Lanthanide-Element Bond Homolysis: Synthetic, Structural, and Bonding Analysis of a Series of Singly Reduced Uranyl–Rare Earth 5f1-4fn Complexes