Nèel temperature variation of CoxNi1−xFe2O4 nanoparticles

CoxNi1-xFe2O4 (x=0.1, 0.3, 0.5) nanoparticles were synthesized by the PVA Sol-Gel method, and all the samples were found to be single phase spinel by powder X-ray diffraction measurements. High temperature Mossbauer spectra were recorded by a Mossbauer spectrometer. Temperature dependence of hyperfine magnetic fields of two magnetic sextets indicates a "two Neel temperatures" phenomenon in Co0.3Ni0.7Fe2O4 and Co0.5Ni0.5Fe2O4, which has been further demonstrated by the magnetic thermo-gravimetric analysis (MTGA). © 2015 Elsevier B.V. All rights reserved.