Exploration of thermoacoustics behavior of water based nickel ferrite nanofluids by ultrasonic velocity method

Magnetic nanofluids (commonly known as ferrofluids) have captured the great attention of the researchers due to their various kinds of applications such as heat transfer, hyperthermia treatments, targeted drug delivery etc. The present experimental investigations deal with the thermoacoustic behaviour of the water based nanofluids of nickel ferrites. The magnetic nickel ferrite nanoparticles were produced by the simple and inexpensive chemical co-precipitation route. The prepared nanoparticles were exposed to different characterization tools for structural, morphological, compositional and magnetic properties analysis. X-ray diffraction analysis with Rietveld refinement confirmed the single phasic nature with nanometric crystallite size of the prepared nanoparticles. Scanning electron microscope images revealed the spherical and nanocrystalline morphology of the prepared nanoparticles. The M-H plot recorded at room temperature revealed the superparamagnetic nature of the nanoparticles. Further, the co-precipitated nickel ferrite nanoparticles with different concentrations were utilized for the preparation of the water based magnetic nanofluids. Colloidal stability of the prepared nanofluids was analyzed by UV–Vis spectroscopy technique and it revealed the stability over 11 days without separation in phase. The temperature dependent thermoacoustic properties of the prepared nanofluids were analyzed through Ultrasonic Interferometer. The interaction between particle–particle and particle–fluid are explained on the basis of thermo-acoustic parameters.