Problems associated with the elimination of significant amounts of oxygen inclusions in sputtered thin films grown in a plasma environment are discussed. In particular data are presented to show that a plasma environment can easily be produced in which the concentration of ground state, excited and ionic oxygen containing species is sufficiently low so that no discernible effects on the magnetic properties of sputtered Permalloy films due to antiferromagnetic inclusions can be detected. Experimental evidence is also given to show that neither the energy of bombarding ion species at the cathode nor the inevitable electron bombardment of the substrate need influence the inducement of a truly uniaxial anisotropy into the NiFe film provided independent temperature control of the film during its growth can be achieved. A comparison between d.c. and asymmetric a.c. as well as substrate biasing with respect to the plasma is made with particular reference to the substrate environment. © 1965, The Electrochemical Society, Inc. All rights reserved.