Dielectric and Impedance Studies of Erbium (Er3+) Ion Substituted Ni-Cu Nanoferrites

• Published in: Brazilian journal of physics 2024-02, Vol.54 (1), Article 1
• Main Authors: Rajashekhar, K., Vinod, G., Naik, J. Laxman
• Format: Article
• Language: English
• Subjects: Ambient temperature; Chemical composition; Condensed Matter; Copper; Erbium; Grain boundaries; Microstructural analysis; Nickel; Permittivity; Physics; Physics and Astronomy; Temperature dependence
• ISSN: 0103-9733; 1678-4448
• DOI: 10.1007/s13538-023-01380-z

Erbium-doped Ni-Cu nanoferrites have been prepared by conventional citrate-gel auto-combustion process. The XRD spectra validated the development of the crystalline phase, tetragonal structure in the pure specimen and the progressive shift to the cubic system of erbium-doped samples. The microstructural analysis was carried out using the scanning electron microscopy (SEM) technique, and elemental mapping images confirmed the elements in the chemical composition. With the help of an LCR meter at ambient temperature, the frequency-dependent various dielectric parameters were measured. The observed dielectric constant and AC conductivity have shown the as-expected behaviour of ferrite samples. In the high-frequency domain, the Er 3+ doping has enhanced the dielectric constant, which varies between 12.65 and 13.45 at 1 MHz and 12.57 and 13.35 at 2 MHz. The AC conductivity was noticed between 1.487 and 1.934 S/cm at 1 MHz and 2.222 and 3.090 S/cm at 2 MHz. The extracted values of grain boundary and grain resistances from cole–cole plots were found in the range of 7.81 × 10 7 to 12.60 × 10 7 Ω and 4.73 × 10 6 to 5.61 × 10 6 Ω and for pure sample 17.6 × 10 7 Ω and 4.5 × 10 6 Ω, which reveals that the resistance due to grain boundaries is more dominating than the grains.