The structural and magnetic properties of bulk polycrystalline CoFe 2O4 and niobium substituted Co1.1Fe 1.85Nb0.05O4 prepared by solid state reaction method, are presented in this paper. The lattice parameter of Co 1.1Fe1.85Nb0.05O4 is seen to be more than that of CoFe2O4. Saturation magnetization, first order magnetocrystalline anisotropy constant calculated using law of approach to saturation and magnetostriction of Co1.1Fe1.85Nb 0.05O4 are seen to be less than those of CoFe 2O4. Longitudinal magnetostriction of Co 1.1Fe1.85Nb0.05O4 measured at room temperature is -123 × 10-6 at a field of 2.2 kOe, with enhanced strain derivative. Field induced trigonal distortion was observed at 2.2 kOe in Co1.1Fe1.85Nb0.05O4 from the analysis of powder XRD patterns. Co1.1Fe1.85Nb 0.05O4 exhibits ferroelectric and magnetoelectric properties. © 2014 Elsevier B.V. All rights reserved.

G. Markandeyulu

Department Of Physics

R. Ramchandra Kiran

R.A. Mondal

Sandhya Dwevedi

DISTORTION (WAVES)

ferrite

Magnetocrystalline anisotropy

Magnetoelectric effects

Magnetostriction

Solid state reactions

ENHANCED STRAINS

LAW OF APPROACHES

MAGNETOCRYSTALLINE ANISOTROPY CONSTANT

Magnetoelectric properties

Room temperature

SOLID STATE REACTION METHOD

Structural and magnetic properties

TRIGONAL DISTORTION

Iron compounds

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

Journal of Alloys and Compounds

Cationic distribution and magnetic properties of partially rare-earth (R) doped NiFe2O4 (NFO) compounds, i.e. NiFe2- xRxO4 (x = 0 and 0.075; R = Gd, Dy and Ho) were investigated, and the results are discussed and presented in this paper. All the compounds were found to stabilize in the cubic inverse spinel structure with the space group Fd3-m. The analysis of the results based on X-ray absorption spectroscopy (XAS) and X-ray magnetic circular dichroism (XMCD) measurements are primarily focused on the valence state information of constituting rare-earth or transition-metal ions, cationic distribution, and the coupling between their magnetic moments. The XAS data revealed that nickel is in Ni2+ valence state while iron is mainly in the Fe3+ valence state though some perceptible traces of Fe2+ were observed. The rare-earth ions are in trivalent states. The partial doping causes differences in the cationic distribution of Ni2+ and Fe3+ ions which obviously results in differences in the net Fe or Ni magnetic moments. Furthermore, 57Fe Mössbauer spectra revealed altered hyperfine field parameters upon the Gd3+, Dy3+ and Ho3+ substitution and all the compounds were found to exhibit collinear ferrimagnetic structures. The results are relevant for the investigation of orientation of individual magnetic moments and to obtain site-specific information related to all the cations involved in the rare-earth doped nickel ferrite structures. © 2019

Journal of Magnetism and Magnetic Materials

Cationic ordering and magnetic properties of rare-earth doped NiFe2O4 probed by Mössbauer and X-ray spectroscopies

Temperature dependence of magnetization, anisotropy, and hyperfine interaction parameters of NiFe2-xYbxO4 (x = 0, 0.05, and 0.075) was investigated, and the results are presented. All the compounds were prepared by solid-state reaction formed in cubic inverse spinel phase with the space group Fd\overline 3 m. Increments in the lattice constant were observed upon partial substitution of Fe3+ by Yb3+. Decreased magnetic moment and increased magnetic anisotropy with Yb3+ substitution were observed through magnetization measurements, carried out at 5, 100, 200 and 300 K. Analyses of Mössbauer spectra recorded at 5 K and 300 K, revealed decreased hyperfine fields and magnetic moments at the B-site (and hence net moment) with increasing Yb3+ content. In addition all the compounds exhibited Neel-type, collinear ferrimagnetic structure. © 1965-2012 IEEE.

IEEE Transactions on Magnetics

Temperature Dependence of Magnetization, Anisotropy, and Hyperfine Fields of NiFe2-xYbxO4 (x = 0, 0.05, 0.075)

Ferromagnetic and ferroelectric characteristics of Gd and Nd-substituted nickel ferrite were investigated. The materials formed in the cubic inverse spinel phase with small amounts of GdFeO3 and NdFeO3 as the additional phases in the respective materials. Substitution of Gd and Nd for Fe caused decrease in the saturation magnetization and Curie temperature of the nickel ferrite. However, the saturation magnetostriction is seen not to change significantly by the substitution of Gd and Nd. The existence of the ferroelectricity was confirmed from the ferroelectric loops and magnetocapacitance of -2% and -3% were observed. The large frequency dependence of the (high) dielectric constant reveals a wide dispersion of relaxation times. The ferroelectric transition temperature values of NiO.Fe1.95Gd0.05O3 and NiO.Fe1.95Nd0.05O3 were found to be 498 and 544 K, respectively. © 2009 Elsevier B.V. All rights reserved.

Magnetoelectric properties of Gd and Nd-doped nickel ferrite

Journal of Materials Research

Improved electrical and dielectric properties of La-doped Co ferrite

Physical Review B

Signature of ferroelectricity in magnetically ordered Mo-dopedCoFe2O4

Journal of Applied Physics

Effect of temperature variation on the magnetostrictive properties of CoAlxFe2−xO4

Cation distribution of titanium substituted cobalt ferrites

Structural, magnetic and magnetoelectric properties of Nb substituted Cobalt Ferrite

Journal	Data powered by TypesetJournal of Alloys and Compounds
Publisher	Data powered by TypesetElsevier Ltd
ISSN	09258388
Open Access	No