Effect of Zn doping on structural, magnetic and dielectric properties of LaFeO3 synthesized through sol–gel auto-combustion process

• We have synthesized the samples of LaFe1−xZnxO3 (0 ≤ x ≤ 0.3) using sol–gel auto-combustion process.
• The doping of Zn2+ hugely enhances the dielectric constant (ɛ′) and it shows a colossal value.
• The parent compound LaFeO3 does not show any relaxation peak, but the substitution of Zn at Fe3+ site brings the relaxation in the system.
• The system shows a peak behavior thereby giving the Debye like dipolar relaxation response.

We have studied the structural and dielectric properties of nano-crystalline LaFe1−xZnxO3 (0 ≤ x ≤ 0.3) pervoskite samples synthesized through sol–gel auto-combustion technique. X-ray diffraction and FTIR spectroscopy are used to confirm the single phase characteristics. Microstructural features are investigated using scanning electron microscope and compositional analysis is performed through energy dispersive spectroscopy. The average grain sizes, calculated from the Scherrer formula, lie in the range below 30 nm. The hysteresis (M-H) curves display a weak magnetic order and a shift in the hysteresis loops. Dielectric response has been discussed, in the framework of “universal dielectric response” model. The value of dielectric constant (ɛ′) increases drastically on Zn doping. The dielectric loss factor (ɛ″) shows Debye like dipolar relaxation behavior. The observed peaks in loss factor (ɛ″) are attributed to the fact that a strong correlation between the conduction mechanism and the dielectric behavior exists in ferrites.

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