Characterization of Mn1.3FeTi2Ow and Fe4Mn6V7Ow Nanocomposites by Ferromagnetic Resonance (FMR)

Nanocomposites based on multicomponent metal oxides, such as Mn1.3FeTi2Ow and Mn6Fe4V7Ow, present tunable structural and magnetic properties with high potential for technological applications. In this study, these nanomaterials were synthesized by urea and chalconcarboxylic acid assisted chemical routes, followed by heat treatments at different temperatures (400°C, 800°C and 1000°C). Magnetic characterization was performed by Ferromagnetic Resonance (FMR) spectroscopy, with analysis of the g factor and the line width at half height (ΔH). The results indicated that increasing the temperature favors the magnetic ordering and the formation of coherent crystalline phases, reflected in the progressive decrease of ΔH and stabilization of the g values. The Mn1.3FeTi2Ow structure showed optimized behavior at 1000°C, while Mn6Fe4V7Ow exhibited significant magnetic improvements already at 800°C. Thermal evolution allowed correlations between structure, magnetic ordering and local anisotropy, demonstrating the potential of these materials for applications in magnetoresistance devices, magnetic sensors, hyperthermia devices and microwave absorption.