Influence of Mn substitution on crystal structure and magnetocrystalline anisotropy of nanocrystalline Co1−xMn x Fe2−2xMn2xO4

Abstract

Nanocrystalline Mn substituted cobalt ferrite Co 1-x Mn x Fe 2-2x Mn 2x O 4 (x = 0.0-0.4) has been synthesized by the standard citrate-gel method. The structural and magnetic characteristics of all samples have been studied using powder X-ray diffraction, Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscope (FE-SEM) and VSM techniques. Distributions of cations between the two interstitial sites (tetrahedral and octahedral site) have been estimated qualitatively by analyzing the powder X-ray diffraction patterns by employing the Rietveld refinement technique. All samples are found to be mixed spinel with cubic structure (Fd 3 À m space group). The FT-IR study shows the presence of absorption bands in the range of 390-750 cm-1 , which confirm the spinel structure of the sample. The stoichiometry of Co, Fe, Mn and O ions in the sample has been obtained by using energy-dispersive spectrum with help of an FE-SEM. The magnetizations in saturation have been analyzed by employing the ''law of approach'' technique. The saturation magnetization, coercivity and magnetocrystalline anisotropy constant depend upon Mn ion concentration and crystallite size.

Optimization of dielectric properties of PVDF–CFO nanocomposites

“…The lattice parameter increases with the decrease in the crystallite size. Similar result has been reported in the litereature . The XRD patterns of nanocomposites are shown in Fig.…”

“…CFO has been prepared by the Sol‐gel method , and heated to 1,000°C. The synthesized sample was ball milled for 24, 48, 72, and 96 h, respectively in order to have different size nanoparticles using steel balls at the speed of 300 rpm.…”

Study on AC permeability and permittivity of manganese doped cobalt ferrite nanoparticles

“…The observed peaks at 27°, 41°, and 49°may be due to the presence of CoFe 2 O 4 [11]. In addition, the extra peaks at 24°, and 33°are observed due to the presence of MnO and Fe 2 O 3 [12]. .…”

“…Cobalt ferrites are reported to be the best example of hard ferrite materials because of their excellent chemical stability, mechanical hardness, reasonable saturation magnetization and high magneto-crystalline anisotropy [1]. They are now being used in high-density recording media, ferro-fluids, magnetic resonance imaging (MRI), biomedical diagnostics, radio frequency hyperthermia and drug delivery as reported elsewhere in literatures [1][2][3][4][5][6][7][8][9][10][11][12]. Cobalt ferrite is of inverse spinel structure with basic formula B (AB) O 4 where relatively larger oxygen ions (O 2 − ) form cubic closed pack (ccp) structure.…”

Ameliorating Physical Properties of Co1-xCaxFe2O4 Nano Ferrites for Technological Applications

“…The spinel ferrites have remarkable physical properties. Among them, CoFe 2 O 4 has attracted more attention due to its interesting magnetic properties like high coercivity, moderate saturation magnetization, chemical stability, good mechanical hardness and large energy products (i.e., MH max ) [5]. It also exhibits high cubic magneto crystalline anisotropy, which is the common feature of spinel ferrite [6].…”