Effect of magnetic field on the growth of α-Fe2O3 thin films by atomic layer deposition

Effect of magnetic field on the growth of alpha-Fe2O3 thin films on soda-lime-glass and alpha-Al2O3(0 0 1) substrates with the atomic layer deposition (ALD) technique is reported. Alterations in texture of the deposited films have been investigated by XRD and TEM, and topography by AFM. It is possible to alter the preferred growth orientation of films on soda-lime-glass substrates from preferred [001] to random polycrystalline orientation by application of a magnetic field. The epitaxial growth on alpha-Al2O3(0 0 1) is, however, not affected by application of a magnetic field. The growth rate of films deposited on soda-lime-glass substrates is reduced by a factor of 3/2 by application of a magnetic field, whereas the growth rate on alpha-Al2O3(0 0 1) is not affected. The complete mechanism behind the occurrence or absence of modified growth in external magnetic fields is not uncovered, but factors such as: presence/absence of iron sites, activation of surface iron to accept thd liberated during the chemisorbtion of Fe(thd)(2), and presence of parasitic ferromagnetism may be of importance in the present case. (C) 2003 Elsevier B.V. All rights reserved.