Dissolution process of copper sulfate into water in a heterogeneous vertical magnetic field

The dissolution process of copper sulfate into water in a heterogeneous magnetic field vertical to the interface was examined from the viewpoint of the self-organization process of the nonequilibrium fluctuations. In a heterogeneous magnetic field, a material receives a magnetic force proportional to the product of the magnetic susceptibility, the magnetic flux density B and its gradient (dB/dz). As the reaction proceeds, a diffusion layer develops in the area where changing susceptibility is formed at the interface because of the dependence of the magnetic susceptibility on the solute concentration. In the case of a vertical magnetic field, a magnetic force is applied to the diffusion layer to induce magnetic force fluctuation and the resultant concentration fluctuation of the solute, which self-organize numerous convection cell. The cell pattern was then observed from the morphology of the dissolved copper sulfate pentahydrate crystal. As a result, it was concluded that the pattern changes from a roll-type to a rectangular-type as the magnetic flux density increases.