An assembly that contains a substrate, nanomagnetic material, and a device for
cooling the substrate. The nanomagnetic material has a mass density of at least
about 0.01 grams per cubic centimeter, a saturation magnetization of from about
1 to about 36,000 Gauss, a coercive force of from about 0.01 to about 5,000 Oersteds,
a relative magnetic permeability of from about 1 to about 500,000, and an average
particle size of less than about 100 nanometers.
