Impact of cobalt doping on magnetic and structural properties in Ce1−xCoxO2 (x = 0.1, 0.2 and 0.3) ceramics synthesized by combustion method.

[Display omitted] • Co doped Ceria, Ce 1-x Co x O 2 (x = 0.1, 0.2, 0.3 mol %) were synthesized by combustion method at 500 °C. • Structure, morphology and spectroscopic studies of the nanopowders were studied. • Room temperature ferromagnetism was observed in this material. In this investigation, cobalt doped ceria nanopowders, Ce 1-x Co x O 2 (x = 0.1, 0.2 and 0.3mol.%) were synthesized by citrate–nitrate auto-combustion method at 500 °C in an open furnace. The prominent X-ray diffraction pattern peaks corresponding to the crystallographic planes (1 1 1), (2 0 0), (2 2 0), (3 1 1), (2 2 2), (4 0 0) and the cell parameters confirm the cubic fluorite crystal structure of the ceria with the help of powder diffraction standard (JCPDS card No.00-034-0394). The UV–Visible absorption due to the charge transfer of O2− → Ce2+ and other functional groups were studied by UV–Visible and FT-IR spectroscopic analyses. The visible light emission (wavelength of 420 nm and 520 nm are corresponding to the defect levels of the O 2p and Ce 4f bands) due to oxygen and other vacancies were confirmed by photoluminescence spectroscopy. Energy band gap (E g) of the Ce 0.9 Co 0.1 O 2 , Ce 0.8 Co 0.2 O 2 and Ce 0.7 Co 0.3 O 2 was found to be 1.423 eV, 1.375 eV and 1.332 eV, respectively. The porosity, agglomeration, particles size, shape and distribution of the synthesized nanoparticles were analyzed by scanning electron microscopy (SEM) and high resolution transmission electron microscopy (HR-TEM). The energy dispersive X-ray spectroscopy (EDX) confirms the presence of constituent elements of Ce 1-x Co x O 2 such as Ce, Co, and O. The existence of weak ferromagnetism and its variation due to cobalt concentration were studied by vibrating sample magnetometry (VSM) at room temperature. [ABSTRACT FROM AUTHOR]