Demonstration of the elusive concentration-gradient paramagnetic force.

Using classical electrochemistry, it is demonstrated that the concentration-gradient paramagnetic force, FnablaC, is a body force proportional to |B|2 acting parallel to the concentration gradient of electrogenerated radicals. FnablaC can balance gravity, holding volumes of solution wherein mass transfer continues to take place by diffusion. In contrast to usual levitation forces, FnablaC does not depend on field gradients and may be present even in homogeneous magnetic fields. Understanding the properties of FnablaC is relevant to magnetic confinement and levitation and is speculated even to propulsion with objects having permanent susceptibility gradients.