Influence of Substrate Processing on the Magnetic Properties and Reproducibility of Evaporated Nickel-Iron Films

Abstract

The properties of evaporated nickel-iron films, deposited on substrates cleaned with detergent only, were observed to vary widely from one evaporation run to another and even within a run. This erratic variation is believed to be due partially to inhomogeneities in the surface structure of the substrates. Several other substrate cleaning techniques were evaluated for their effectiveness in reducing this variation in film properties. As a result, both wall motion and rotational threshold have been lowered, and the average percentage variations of the magnetic properties have been considerably reduced. Because of the resulting improvement in film reproducibility, it has been possible to verify the predicted dependence of domain wall coercive force on film thickness, even for films which had been deposited in separate evaporations.