An ultrasonic characterization of ferrofluid.

Nanoparticles of Cr(2)O(3) are prepared through hydrothermal synthesis process using CrO(3)/PVA in aqueous solution using sucrose as a reducing agent. The calcination temperature is taken 300 and 350 degrees C. XRD and SEM of the powdered Cr(2)O(3) particles are done for the characterization. The average particle size is found 30-80 nm. It is found that average particle size increases with calcination temperature. The UV-visible absorption spectra are taken for the study of photo-physical properties of ferrofluids. Ultrasonic velocity and absorption measurements are performed in Cr(2)O(3) ferrofluid using variable path interferometer and pulse-echo techniques, respectively. The achieved results are discussed in correlation with the magnetic and other physical properties of Cr(2)O(3).