Dielectric, XPS, and ferromagnetic relaxation studies of Ho-substituted polycrystalline magnetic oxide materials. Issue 21 (1st November 2022)

• Record Type: Journal Article
• Authors: Manzoor, Alina; Azhar Khan, Muhammad; Afzal, Amir Muhammad; Arshad, Muhammad Imran; Shahzad, Aamir; Akbar, Sofia; Kashif, Muhammad; Ashraf, Ghulam Abbas; Khan, Muhammad Yaqoob; Rasul, M. Nasir; Shifa, Muhammad Shahzad; Nasar, Gulfam; Hussain, Altaf
• Is Part Of: Ceramics international. Volume 48:Issue 21(2022)
• Page Start: 32266
• Page End: 32272
• Publication Date: 2022-11-01
• Subjects: Nanomaterials -- FMR linewidth -- XPS -- Resistivity -- Seebeck coefficient; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2022.07.168
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: The impact of holmium (Ho) ions on lithium-rich spinel ferrites is studied through magnetic, morphological, and electrical transport properties. The X-ray photoelectron spectroscopy (XPS) analysis indicated the existence of all metal ions in the required valence state. Transmission electron microscopy (TEM) analysis exhibited nano-crystalline (∼50 nm) structures of these ferrites. The electrical resistivity measurements showed the higher resistivity values of the synthesized samples. The resistivity increased from 2.4 × 10 8 to 2.1 × 10 10 Ω-cm with Ho inclusion, indicated an inverse relation with the size of grains. The Curie temperature ( T c ) observed to decrease from 848 to 806 K with the incorporation of Ho 3+ ions. The activation energy (Δ E a ) noted to vary between 0.21 and 0.23 eV. The drift mobility ( μ d ) study revealed a decrease from 1.86x10 −12 to 6.14x10 −14 cm 2 V −1 s −1 by increasing Ho amount up to x = 0.06. A reduction in thermoelectric power (S) from -143 to -95 μ.V/K by increase in Ho concentration confirmed the Fe replacement by Ho on octahedral B-sites. The ferromagnetic resonance (FMR) investigations indicated a drop in FMR line-broadening (ΔH) from 2491 to 2000 Oe by the increase of Ho concentration, making it beneficial to reduce microwave losses. A non-linear variation in the resonance field ( H res ) with the substitution of Ho was observed between 7359 to 7785 Oe.