Ultrasonic Studies on Magnetite (Fe3O4) Nanoparticles at 303.15 K

In this work, ultrasonic studies of iron (III) oxide (Fe3O4) nanofluids are reported. Two different sized nanoparticles were used, one is commercially procured and the other is synthesized with a size of 9 +/- 3 nm in laboratory by co-precipitation method. The synthesized nanoparticles are characterized by X-ray powder diffractometry (XRD) to find crystallinity and composition and scanning electron microscopy (SEM) to analyze the surface morphology of nanoparticles. Ultrasonic velocity and density were measured for all the prepared samples of nanofluids of different concentration at 303.15 K and atmospheric pressure by using DSA 5000 M. The acoustical parameters such as adiabatic compressibility, intermolecular free length, molar sound velocity and acoustic impedance and their excess values were calculated from the experimental data. Molecular interactions in these solutions were analyzed on the basis of the variation of different concentration at 303.15 K. It is observed that ultrasonic velocity shows non-linearity with particle concentration and the results are discussed in terms of particle-particle and particle-fluid interactions.