The effect of self-diffraction in magnetic fluids

Structure of transformer oil-based magnetic fluids studied using acoustic spectroscopy

“…With increasing magnetic field, the acoustic attenuation from the beginning increases, because the interactions between the magnetic field and the magnetic moment of the nanoparticles leads to aggregation of particles and clusters formation (structures as long as hundreds of nanometers [1,11,14]). The behavior for higher magnetic fields ð 4120 mTÞ depends on the kind of MF (carrier liquid), concentration of nanoparticles and temperature.…”

“…A MF is a colloidal suspension of nano-sized magnetic particles covered with a surfactant layer in a carries liquid [1,3,9,10]. Particles (usually ferrites) due to their small core diameters (4-20 nm) are generally monodomain and to prevent the interaction among them that may lead to their agglomeration and subsequent sedimentation they are coated by surfactants that produce entropic repulsion.…”

“…Magnetic fluids (MF) have attracted remarkable physical properties that have recently found wide application in technology [1][2][3][4] and medicine [5,6]. The transformer oil-based MF prepared by adding magnetic nanoparticle suspension to transformer oil with the purpose to improve some of the oil's insulating and thermal properties is an innovating example of the development in power electronic technology.…”

Negative Thermophoretic Force in the Strong Coupling Regime

“…This is known as positive thermophoresis, and it is commonly understood as the result of more momentum transfer from solvent particles on the hot side than on the cold side. However, various particles such as colloids [3][4][5], polymers [4][5][6], charged nanoparticles [5,[7][8][9], magnetic particles [3], fullerenes [10], proteins [5,11] and vesicles [12] have been observed to migrate from cold to hot. These observations suggest that there is more to thermophoresis than plain momentum transfer resulting from collisions between hard particles.…”

Thermal Diffusion Shock Waves

“…A self-diffraction experiment [17] was carried out by passing the 532 nm beam from a frequency doubled, continuous Nd : YVO 4 laser through a Galilean telescope and dielectric beam splitter and recombining the resulting two laser beams in a 10 m path length Pyrex cell to form a temperature grating, as shown in Fig. 3.…”