title: Magnetic and ultrasonic studies on stable cobalt ferrite magnetic nanofluid.
abstract: Stable cobalt ferrite nanofluids of various concentrations have been prepared through co-precipitation method. Structural and morphological studies of nanoparticles are made with the help of X-ray diffraction technique and Transmission Electron Microscope respectively and it is found that the particles exhibit face centered cubic structure with an average size of 14 nm. The magnetic properties of the nanofluids have been analyzed at room temperature which revealed ferromagnetic behavior and also the very low value of coupling constant which ensures the negligible interparticle interaction in the absence of magnetic field. Ultrasonic investigations have been made for the nanofluids at different temperatures and magnetic fields. The temperature effects are explained with the help of open and close-packed water structure. The inter particle interactions of surface modified CoFe2O4 particles and the cluster formation at higher concentrations are realized through the variations in ultrasonic parameters.
authors.affiliation: Advanced Materials Lab, Department of Physics, National Institute of Technology, Tiruchirappalli, Tamilnadu 620 015, India.
authors.forename: M
authors.initials: M
authors.lastname: Nabeel Rashin
authors.affiliation: Advanced Materials Lab, Department of Physics, National Institute of Technology, Tiruchirappalli, Tamilnadu 620 015, India. Electronic address: hemalatha@nitt.edu.
authors.forename: J
authors.initials: J
authors.lastname: Hemalatha
mesh_terms: D003035:Cobalt / Q000737:chemistry* / Q000528:radiation effects; D005290:Ferric Compounds / Q000737:chemistry* / Q000528:radiation effects; D019220:High-Energy Shock Waves; D060526:Magnetic Fields; D008422:Materials Testing / Q000379:methods*; D053758:Nanoparticles / Q000737:chemistry* / Q000528:radiation effects; D010316:Particle Size; D012996:Solutions / Q000737:chemistry* / Q000528:radiation effects; D014463:Ultrasonography / Q000379:methods*
chemical_list: D005290:Ferric Compounds; D012996:Solutions; C001215:ferrite; D003035:Cobalt
keywords: Adiabatic compressibility; Ferrofluid; Molecular interaction; Nanofluid; Ultrasonic velocity