Magnetothermal Convection in Insulating Paramagnetic Fluids

When an insulating paramagnetic fluid such as gaseous oxygen is subjected to combined thermal and magnetic field gradients, a magnetic body force is shown to exist which is analogous to that of gravity. It is shown both theoretically and experimentally that this magnetic body force can be larger in magnitude than that due to gravity for gaseous oxygen for even modest values of the magnetic field strength-gradient product. The possibility of magnetic control of thermal convection is discussed for several instances. The application of this effect to control thermal convection during crystal growth from paramagnetic liquids is discussed in detail.