Dynamics of concentration profiles of nano-sized magnetic particles in a non-uniform magnetic field

A. Mezulis - D. Zablotsky - E. Blums

Institute of Physics, Latvian University, 32 Miera str., Salaspils-1 LV-2169, Latvia

Abstract
Results of numerical and experimental investigation of nano-sized magnetic particles diffusion in a non-uniform magnetic field are presented. Diffusion of the nanoparticles is studied in a 2D Hele-Shaw cell submitted to a magnetic field gradient along the vertical axis. An optical interferometry method (particularly, Mach-Zehnder interferometer) is applied to read the concentration profile by proceeding the time. Experiments confirm the theoretical prediction of a ``negative region'' of the concentration profile in the middle of the Hele-Shaw cell, i.e. \drϕ/\dr H < 0. The concentration profile is calculated numerically from the conservation equation and compared with the experimental results and with the analytical solution in the boundary layer approximation. Tables 1, Figs 3, Refs 5.