Interplay of structural, optical, and magnetic properties of Ce1-xNdxO2-δ nanoparticles with electronic structure probed using X-ray absorption spectroscopy

Abstract

The CeO2-δ and Ce1-xNdxO2-δ (x = 0.02, 0.04 and 0.06) nanoparticles, synthesized by microwave assisted co-precipitation method have been investigated for structural, optical, electronic structure and magnetic properties using X-ray diffraction, transmission electron microscopy, Absorption spectroscopy, surface enhanced Raman spectroscopy, X-ray absorption spectroscopy (XAS), and SQUID magnetometer. TEM and XRD measurements indicate face-centred cubic fluorite structure of CeO2 with Fm-3m space group. The Raman spectroscopy indicates that all the Nd3+-doped CeO2 samples downward shifting of F2g band with introduction of oxygen vacancies. Further, band gap decrement has been observed with incorporation of Nd3+ ions in CeO2 lattice. The XAS spectra of Ce M − edge clearly indicate changed valence state of Ce ions from Ce4+ to Ce3+ with Nd3+ doping concentrations. The formation of oxygen vacancies is also confirmed with O K- and Nd M-edges XAS analysis. It is revealed that new complexes Ce3+-VO- Nd3+ and Ce4+- VO –Ce3+ have been introduced to support FM ordering through the development of F+-centres. Therefore, it can be concluded that oxygen vacancies play a prominent role in improving the ferromagnetic and various properties of these nanomaterials, to make them suitable for many applications as UV blocker, Photocatalyst, Spintronics and Optoelectronics applications.