Abstract

We report on the measurement and simulation of the field-dependent polarized neutron reflectivity (specular) and scattering (off-specular) for an antiferromagnetically coupled Co/Cu multilayer (ML) with number of bilayers N=40. The first-order Bragg peak is visible in the non-spin flip (NSF) channels representing the bilayer periodicity. We observe off-specular intensity around the AF Bragg peak at the half-order position in both SF and NSF channels. These Bragg sheets are most intense at lower fields and gradually disappearing at higher fields as the system attains saturation. We attribute the Bragg sheets to vertically correlated AF domains along the ML stack which get bigger in size with field strength. Those interpretations are confirmed by simulation of the data within the distorted wave born approximation (DWBA).

Keywords: Polarized neutron reflectometry; Magnetization reversal mechanisms; Off-specular scattering

PACS: 61.12.Ha; 75.30.Gw

Article Outline

References

(25K)
Fig. 1. MOKE hysteresis loop and the GMR curve for the ML . Circled numbers are the fields of Neutron measurements which are shown.

(149K)
Fig. 2. Experimental NSF and SF intensity maps of a at 20, 100 and 500 Oe (circled in Fig. 1). Off-specular intensity appears around the AF Bragg peak () in SF and NSF channel for lower fields but is gradually disappearing at higher fields.

(47K)
Fig. 3. Simulated NSF and SF intensity maps of a at 100 Oe. The data is simulated within the DWBA.

References

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Corresponding author. Fax: +49 2461 61 4443.