ISSN:
1089-7550
Source:
AIP Digital Archive
Topics:
Physics
Notes:
It is well established that magnetic interactions in particulate media and films can be assessed on the basis of the correlation between the normalized dc demagnetization remanence, Id(H), and the normalized isothermal remagnetization remanence, Ir(H). Departures of Henkel plots from the straight-line relationship of the Wohlfarth equation may be regarded as a measure of the strength of the intergranular field interactions in thin films. Delta-I plots are commonly used to manifest these interactions. These remanence techniques have been applied to both ordered and highly disordered (granular) sputtered multilayers of Co/Cu in which the giant magnetoresistance effect has been observed. Both the Henkel plots and the delta-I (MR) plots exhibit oscillatory characteristics, which correlate with magnetoresistance and critical field data. Figure 1 shows the amplitude of the delta-I plot as a function of Cu volume fraction in quasigranular Co/Cu films in good correlation with the amplitude of the giant MR effect. Similar results have been obtained even with relatively thick multilayers of Fe/Cu in which the giant MR is extremely weak. These results would seem to indicate that comprehensive remanence measurements involving Henkel and/or delta-I plots are effective in evaluating intergranular exchange coupling in giant MR film systems, given that these plots can be processed to provide quantitative interaction field data.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.352612
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