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

• Published in: Materials chemistry and physics Vol. 181; pp. 432 - 443
• Main Authors: K., Chandra Babu Naidu, W., Madhuri
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15-09-2016
• Subjects: Dielectric; Electrical conductivity; Impedance; Magnetic; Microstructure; Microwave synthesis; Microwave synthesis; Electrical conductivity; Magnetic; Microstructure; Dielectric; Impedance
• ISSN: 0254-0584; 1879-3312
• DOI: 10.1016/j.matchemphys.2016.06.079

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.
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•M-H loop attributes ferri to paramagnetic transition of Microwave sintered NiMgZn ferrites.•Mr ∼3 × 10−4–2.4 × 10−2 emu/g reveal the weak super para magnetic particles.•Cation distribution is made from magnetic moment of all samples.•High εr and low Hc attribute super capacitors and recording applications.•Nyquist plots confirm the semiconducting nature of all compositions.