Improved electrical, dielectric and magnetic properties of Al-Sm co-doped NiFe2O4 spinel ferrites nanoparticles

• Published in: Materials science & engineering. B, Solid-state materials for advanced technology Solid-state materials for advanced technology, 2019-04, Vol.243, p.47-53
• Main Authors: Sartaj Aziz, Hafiz, Ali Khan, Rafaqat, Shah, Faheem, Ismail, Bushra, Nisar, Jan, Mujtaba Shah, Syed, Rahim, Abdur, Rahman Khan, Abdur
• Format: Article
• Language: English
• Subjects: Aluminum; Ascorbic acid; Chemical synthesis; Coercivity; Crystallization; Dielectric loss; Dielectric properties; Magnetic materials; Magnetic measurement; Magnetic properties; Magnetic saturation; Magnetism; Morphology; Nanoparticles; Nickel ferrites; Remanence; Samarium; Scanning electron microscopy; Spinel; Thermogravimetric analysis; X-ray diffraction
• ISSN: 0921-5107; 1873-4944
• DOI: 10.1016/j.mseb.2019.03.021

•Al3+ and Sm3+ ions were successfully doped into the spinel lattice of NiFe2O4.•Improved ‘Ms’ (53.79 emu/g) for the sample NiFe1.7Al0.15Sm0.15O4.•Resistivity is enhanced for doped compositions of spinel nickel ferrites. This study reports the effects of aluminum and samarium on the structural, electrical and magnetic properties of NiFe2O4 spinel ferrites. Nanoparticles were prepared by hydrothermal method in the presence of ascorbic acid and urea. Thermogravimetric analysis revealed no weight losses above 923 K and therefore all samples were annealed at 1023 K to avoid extra phases. X-ray diffraction analysis confirmed well crystallized single-phase spinel structure for all the compositions. The morphology of the particles did not change significantly with dopant contents as evident from scanning electron microscopy. The room temperature electrical resistivity was observed to increase with content of Al3+ and Sm3+ ions following the Verwey’s hopping mechanism. The dispersion in the dielectric constant and dielectric loss with applied frequency in the range of 0.0–3.0 GHz, exhibited normal behavior of ferrites. The magnetic measurements indicated increase in saturation magnetization till x = 0.15. Coercivity and remanence were observed to decrease with Al-Sm contents.