Size dependent magnetic properties and cation inversion in chemically synthesized MnFe2O4 nanoparticles

Abstract

Rietveld structure refinement, cation distribution and magnetic properties of Al3+ substituted NiFe2O4 nanoparticles J. Appl. Phys. 109, 053909 (2011); 10.1063/1.3559266 Control of the cation occupancies of MnZn ferrite synthesized via reverse micelles Structure and magnetic properties of rf thermally plasma synthesized Mn and Mn-Zn ferrite nanoparticlesMnFe 2 O 4 nanoparticles with diameters ranging from about 4 to 50 nm were synthesized using a modified coprecipitation method. X-ray diffractograms revealed a pure phase spinel ferrite structure for all samples. Transmission electron microscopy showed that the particles consist of a mixture of both spherical ͑smaller͒ and cubic ͑larger͒ particles dictated by the reaction kinetics. The Néel temperatures ͑T N ͒ of MnFe 2 O 4 for various particle sizes were determined by using high temperature magnetometry. The ϳ4 nm MnFe 2 O 4 particles showed a T N of about 320°C whereas the ϳ50 nm particles had a T N of about 400°C. The high Néel temperature, compared with the bulk MnFe 2 O 4 T N of 300°C, is due to a change in cation distribution between the tetrahedral and octahedral sites of the spinel lattice. Results of extended x-ray absorption fine structure measurements indicate a systematic change in the cation distribution dependent on processing conditions.

Effect of ZnO on Structural and Magnetic Properties of MnFe2O4/ZnO Nanocomposite

“…Similar results have been reported in literature [11,[23][24][25]. Finite size effects such as cation distribution and oxidation [27].…”

Structural characterization and multiferroic properties of hexagonal nano-sized YMnO3 developed by a low temperature precursor route

“…reverse micelles, 11 solvothermal, 12 sonochemical 13 and polymeric citrate precursor 14 methods are available in literature for the fabrication of various nanostructures. [21][22][23] This mechanism is not been reported for YMnO 3 . Nanocrystalline YMnO 3 has been prepared by hydrothermal 16 and solgel [17][18][19] methods.…”

A general approach to the synthesis and detailed characterization of magnetic ferrite nanocubes

“…52 , the magnetic coupling purely originated from the Fe ions, and is relatively weak. Raman structural analysis, Mn 2+ , mainly replaced the Fe 2+ at octahedral sites, which resulted in only a slight magnetic moment decrease, but did not significantly affect the magnetic properties (Fig.…”