Paramagnetism found in Mn-doped CuO nanofibers at room temperature explained by XPS , XAS and Rietveld method

Abstract

CuO and 3 % Mn-doped CuO nanofibers were synthesized employing the electrospinning method. X-ray diffraction (XRD) verified a monoclinic phase with a C 2/c space group. An electronic density analysis, obtained using Fullprof software, was projected on the (110) and (001) planes for both materials, showing modifications in the Cu positions. This fact generated vacancies involved in the paramagnetism formation in the Mn-doped CuO nanofibers, in contrast to the mixed magnetic phase composed by both ferromagnetic and paramagnetic behaviors found in the undoped CuO. The vacancy amount was quantified by X-ray absorption spectroscopy (XAS) applying CASTEP software. In addition, an analysis from Cu 2p XPS peaks supports the predicted Cu-Cu rearrangement by the Fullprof software study, while the presence of Cu1+ confirms the substitution of Mn for Cu in the doped sample.