Optical and magnetic properties of fluoride-doped CeO2 obtained by an oxidative insertion method

Abstract

• CeO 2 : F sample is synthesized using molten flux promoted oxidative insertion method. • PXRD and Raman spectral measurements confirmed the fluorite structure of CeO 2 :F. • Besides Ce and O, EDX analysis also revealed the presence of 18 at. % of fluoride. • PL and magnetic studies revealed a lower concentration of O vacancies in CeO 2 :F. • The F-doped sample had a higher concentration of Ce 3+ in CeO 2 :F. In the present study, we generated a fluoride-doped CeO 2 sample through the molten hydroxide flux promoted oxidative insertion approach using CeF 3 as the precursor. We analyzed the results and compared them with pure CeO 2 prepared by the same approach starting from Ce(NO 3 ) 3 . High-resolution powder X-ray diffraction, FTIR, and Raman spectral measurements confirmed both samples’ fluorite structure. The CeO 2 resulted from the oxidative flux treatment of CeF 3 had 18 at.% of fluoride ion-doped in it. The optical band gap narrowed marginally from 2.98 to 2.88 eV upon fluoride doping in CeO 2 . The blue emission intensity decreased with fluoride doping, indicating a reduction in oxygen vacancies compared to undoped CeO 2 . F-doped CeO 2 showed ferromagnetic behavior with magnetization, H c, and M r values higher than the undoped sample. A higher concentration of Ce 3+ and a lower concentration of oxygen vacancies were the consequences of fluoride doping in CeO 2 by this synthetic method.