Unidirectional Hysteresis in Thin Permalloy Films

Variations in the magnetic anisotropy properties of epitaxialCrO2films as a function of thickness

“…6͒, a spring magnet spin configuration is produced, with a bottom layer of ϳ9 nm, a soft layer of ϳ46 nm, and the remaining thickness for the top layer. The hysteresis loops should contain two separate switching fields in this case, and each set of switching fields roughly obey a Kondorskii-type domain wall motion, 27,28 as observed in our samples. Despite the success in predicting the double switching behavior, the remnance from the actually measured hysteresis loops does not exactly match the calculated values ͑around 75% for magnetic fields along the c-direction, and 45% along the b-direction͒.…”

“…The magnetic axis changes from the c direction in the thick film to the b direction in the thin film. As has been previously shown, 19 the hysteresis loops of epitaxial ͑100͒ CrO 2 films can be reasonably described by coherent rotation of M followed by Kondorskii-type domain wall motion, 27,28 where the magnetic reversal occurs when the projection of the applied field on the magnetic easy direction reaches a critical value, i.e., H s ͑͒cos = H s ͑0͒, where is the angle between the applied field and the easy axis.…”

Permanent Magnet Materials

“…The position with regard to Alnico-type alloys seems to have improved since 1959, as the measurements [7, 7a] now show that the face-centered cubic phase contributes little to optimum magnetic properties of standard Alnico, and that the relation between these properties and the precipitate structure is more clear cut than was thought earlier. Finally, the magnetic properties of thin films (see, for example, references [10] and [11]) can now also be discussed to some extent in fine particle terms. Finally, the magnetic properties of thin films (see, for example, references [10] and [11]) can now also be discussed to some extent in fine particle terms.…”