HALL-EFFECT, RESISTIVITY AND MAGNETIC-MOMENT OF AMORPHOUS AND POLYCRYSTALLINE IRON FILMS

Thin films of iron were prepared by condensation from the vapour phase onto a liquid helium-cooled substrate. The 'as deposited' films possessed large resistivities similar to that of liquid iron and were ferromagnetic. The extraordinary and ordinary Hall coefficients of the films were measured and were found to be of the order of fifty times greater than their crystalline counterparts, although the films possessed a magnetic moment of up to 50% smaller. On annealing these quantities, at a specific temperature, irreversibly changed to values similar to those of the crystalline state. Results are presented for the Hall coefficients of the annealed polycrystalline films from 4.2-500K.