PbFe12-xO19-δ (x= 0, 0.25, 0.50, 0.75 &amp; 0.1) ceramics are synthesized via sol-gel auto-combustion technique and sintered at a temperature of 900°C for 45 min. using microwave furnace. The XRD confirms the M-type hexagonal phase and the crystallite size arefound to be varying between 11-45 nm. High dielectric constant (ϵr) of 140.09 and low loss (tan δ) of 0.057 are noticed at 5 MHz which makes these hexaferrites suitable for high capacity condenser and low electric noise device manufacturing applications. © 2016 Author(s).

Prathap R

Department of Computational Intelligence

School of Computer Science and Engineering

Vellore Campus

Madhuri W

Department of Physics

School of Advanced Sciences

Naidu K.C.B

Vellore Institute of Technology (VIT) is a private university located in&nbsp;Tamil Nadu, India. Founded in 1984, as Vellore Engineering College, the institution offers 20 undergraduate, 34 postgraduate, four integrated and four research programs. It has campuses in Vellore, Amravati, Bhopal and Chennai.

VIT is one of the top ranked private universities in India according to NIRF, THE and QS Rankings.&nbsp;Govt. of India has recognized&nbsp;VIT, Vellore as an&nbsp;Institution of Eminence. This has allowed VIT to take independent quality initiatives and move up in world ranking.

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VIT University

Ferroelectric behaviour of microwave sintered iron deficient PbFe12O19-δ

AIP Conference Proceedings

The effect of iron deficiency on the structural, electrical and magnetic properties of the nano PbFe12-xO19-δ (where x = 0.0, 0.25, 0.50, 0.75 and 1.0) hexaferrites prepared by sol-gel auto combustion and further processed by microwaves is presented. The structure studied using transmission electron microscope (TEM) showed hexagonal cylindrical particles with an average size of ∼20 nm. Selected area electron diffraction (SAED) reflected highly crystalline nature of these nanoparticles. From the dielectric characterizations ac-conductivity, dielectric constant and loss tangent are analysed for pure and modified PbFe12-xO19-δ hexaferrites. The magnetic analysis revealed the formation of single-domain structure. Saturation magnetization (MS) decreases from 63.2 (x = 0) to 38.2 (x = 1.0) emu/g with increasing the Fe ions deficiency. Room temperature Mössbauer spectra show five sextets for all compositions confirmed the single phase formation. The relative area of 12k (↑) site decreases and 4f2 (↓) increases drastically with increasing the Fe ions deficiency in Pb-hexaferrites. © 2018 Elsevier B.V.

Materials Chemistry and Physics

Effect of non-stoichiometry in lead hexaferrites on magnetic and dielectric properties

The spinel ferrite of compositions Ni0.2Mg0.8−x ZnxFe2O4 (x = 0.2, 0.4, 0.6, 0.8) are synthesized using microwave double sintering technique. X-ray diffraction study reveals formation of single phase spinel cubic structure. The lattice parameter (a), average crystallite size (D) and bulk density (ρb) are increasing with zinc content. Fourier-transform infrared spectra are recorded to locate octahedral and tetrahedral sites. The dielectric constant (εr), loss tangent (tanδ), ac, dc-electrical conductivities (σac and σdc) are increasing while Curie transition temperature (Tc) and activation energies (Ea) are decreasing with zinc substitution. Power law fit is applied to logσ versus logω plots to evaluate dc-electrical conductivity and exponent (n) at room temperature. Electrical conduction mechanism and relaxation time (τ) are reported from impedance analysis. Hysteresis loop attributes that saturation magnetization (Ms), anisotropy constant (K1) and coercivity (Hc) are decreasing with substituent. Low coercivity of 1.96–2.89 G obtained is suitable for magnetic recording applications. © 2016 Elsevier B.V.

Microwave assisted solid state reaction method: Investigations on electrical and magnetic properties NiMgZn ferrites

Magnesium ferrite nano-crystallites are synthesized by hydrothermal technique. The pure cubic spinnel phases are formed there by microwave heating at 500°C for 10 min. Average crystallite size is found to be of order 42.4 nm using diffraction studies. The largest specific surface area of 65.1 m2/g is achieved for MgFe2O4 nano-crystallites. The morphology is analysed by field emission scanning electron microscope and transmission electron microscope. Dielectric studies reports the dielectric constant (ϵr) of 12.6 and low loss tangent (tan δe) 0.067 which are suitable for microwave device applications. Low ac-conductivity (σac) of 2.4 x10-6 S/cm is obtained for nano ferrite. © 2016 Elsevier Ltd. All rights reserved.

Materials Today: Proceedings

Microwave Hydrothermal Synthesis: Structural and Dielectric Properties of nano MgFe2O4 Ceramics

Journal of Magnetism and Magnetic Materials

A comparative study on the magnetic and electrical properties of MFe 12 O 19 (M=Ba and Sr)/BiFeO 3 nanocomposites

Physica B: Condensed Matter

Magnetic behavior and dielectric properties of aluminum substituted M-type barium hexaferrite

Journal of Alloys and Compounds

Influence of Pb doping on structural, electrical and magnetic properties of Sr-hexaferrites

Complex permeability of Fe-deficient Ni–Cu–Zn ferrites

The Journal of Physical Chemistry A

Ab Initio Study of the Crystallographic Solvation Pattern of the Cytosine-Guanine Base Pair in DNA

Journal	AIP Conference Proceedings
Publisher	Author(s)
ISSN	0094243X
Open Access	0