Evidence of particle-particle interaction quenching in nanocomposite based on oleic acid-coated Fe^sub 3^O^sub 4^ nanoparticles after over-coating with essential oil extracted from Croton cajucara Benth

• Published in: Journal of magnetism and magnetic materials Vol. 466; p. 359
• Main Authors: Medrano, JJA, Aragón, FFH, Leon-Felix, L, Coaquira, JAH, Rodríguez, AFR, Faria, FSEDV, Sousa, MH, Ochoa, JC Mantilla, Morais, PC
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier BV 15.11.2018
• Subjects: Air conditioning; Chemical synthesis; Coating; Image transmission; Iron oxides; Magnetic permeability; Magnetic properties; Magnetism; Nanocomposites; Nanoparticles; Oleic acid; Particle interactions; Quenching; Thermogravimetric analysis; Transmission electron microscopy; X-ray diffraction
• ISSN: 0304-8853; 1873-4766

This study reports on the synthesis and characterization of oleic acid (OA)-coated Fe3O4 nanoparticles (Fe3O4@OA) and AO plus essential oil (EO)-coated Fe3O4 nanoparticles (Fe3O4@OA/EO). The EO was extracted from Croton cajucara Benth (CCB) leaves; a plant from the Brazilian Amazon region. Structural and morphological characterizations were carried out using X-ray diffraction (XRD) and transmission electron microscopy (TEM) images, respectively. Additionally, thermogravimetric analysis and magnetization measurements (hysteresis cycle, zero field-cooled-ZFC, field-cooled-FC, and AC susceptibility) were used to assess thermal and magnetic properties of the as-fabricated samples. Rietveld refinement of XRD pattern confirmed the formation of magnetite phase with no extra phases, whereas TEM images revealed spherically-shaped nanoparticles in the Fe3O4@OA and (Fe3O4@OA/EO) samples with a mean physical size of 8.5 nm and 10.1 nm, respectively. ZFC and FC curves revealed the occurrence of blocked/frozen state below the maximum peak (Tmax) at ∼81 K and ∼40 K for the Fe3O4@OA and (Fe3O4@OA/EO) samples, respectively. Moreover, low-temperature AC susceptibility vs. T curves recorded in the range of 0.2–1000 Hz showed that the OA coating of the Fe3O4 nanoparticles leads to a spin-glass-like behavior credited to the strong particle-particle interactions; meanwhile, the double layer (AO + EO) coating of the Fe3O4 nanoparticles remarkably quenches the particle-particle interaction leading to a superparamagnetic-like behavior.