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Helical spin-density waves in Fe/Cr trilayers with perfect interfaces

R. S. Fishman

Solid State Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6032

Despite the presence of only collinear, commensurate (C) and incommensurate (I) spin-density waves (SDWs) in bulk Cr, the interfacial steps in Fe/Cr multilayers are now believed to stabilize a helical (H) SDW within the Cr spacer. Yet HSDWs were first predicted in an Fe/Cr trilayer with perfect interfaces when the orientation of the Fe moments does not favor C ordering: if the number of Cr monolayers is even (odd) and the Fe moments are pointing in the same (opposite) direction, then a CSDW does not gain any coupling energy. Under these circumstances, a simple model verifies that H ordering is indeed favored over I ordering provided that the Fermi surface mismatch is sufficiently small or the temperature sufficiently high. ©1999 American Institute of Physics.

PII: S0021-8979(99)67508-9
doi:10.1063/1.369900
PACS: 75.70.Cn, 75.50.Bb, 75.50.Ee, 75.30.Fv, 75.30.Cr, 71.18.+y, 75.40.Mg        Additional Information

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