Effect of Magnetic Fields Upon Thermal Conductivity of Iron, Copper, Gold, Silver and Zinc

Abstract

A "bar method" was used to measure thermal conductivity and electrical resistivity for iron, copper, gold, silver and zinc in and out of a longitudinal field of 10,000 gauss, and transverse fields of 8,000 and 4,000 gauss. Copper-constantan thermo-couples "spot" welded to the bars were used to measure the temperatures. For iron, the 10,000 gauss longitudinal field caused a 1.14 percent decrease in heat conductivity and the transverse field of 4,000 gauss caused a 0.4 percent decrease. Electrical resistivity was increased 0.2 percent by the 10,000 gauss field. For copper, the thermal conductivity was decreased 0.23 percent by the 10,000 gauss field. In all the other cases the fields were shown to produce no effects large enough to detect, although the method would readily show any change as great as 0.04 percent. Zinc was used in the ordinary cast form, and in the slowly grown crystal bars. The values of electrical and thermal conductivity were higher in the crystal bar, but the magnetic fields produced no change in either bar. Thus, contrary to theories of Livens and others, these metals failed to show an increase in thermal conductivity in strong fields.