Influence of in-plane crystalline quality of an antiferromagnet on perpendicular exchange coupling and exchange bias

Physical Review B - Condensed Matter and Materials Physics

Volumn 65, Issue 13, 2002, Pages 1-8

  Fitzsimmons, M R ^a   Leighton, C ^b,f   Nogues J ^c   Hoffmann, A ^a,g   Liu, Kai ^b,h   Majkrzak, C F ^d   Dura, J A ^d   Groves, J R ^a   Springer, R W ^a   Arendt, P N ^a   Leiner, V ^e   Lauter, H ^e   Schuller, Ivan K ^b  

^a LOS ALAMOS NATIONAL LABORATORY   (United States)

^b UNIVERSITY OF CALIFORNIA   (United States)

^c UNIVERSITAT AUTÒNOMA DE BARCELONA   (Spain)

^d NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY   (United States)

^e INSTITUT LAUE LANGEVIN   (France)

^f UNIVERSITY OF MINNESOTA   (United States)

^g ARGONNE NATIONAL LABORATORY   (United States)

^h UNIVERSITY OF CALIFORNIA   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 85038315850     PISSN: 10980121     EISSN: 1550235X     Source Type: Journal    
DOI: 10.1103/PhysRevB.65.134436     Document Type: Article

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37. "+" and "-" refer to whether the neutron spin is antiparallel or parallel, respectively, to the applied field.
38. For example, the variation of (formula presented) with depth into the film can be obtained from PNR. To date measurements of SF scattering to momentum transfer Q as large as 2 (formula presented) for (formula presented) and (formula presented) films have been obtained (by us) and the results indicate the magnetization in the F layer is uniform across the thickness of the film.
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43. We note that the neutron reflectivity profiles from sample u-AF cooled in a field applied at 45° to the anisotropy axis were symmetric, and the SF scattering intermediate between those shown in Figs. 11(b) and 22(b).
44. The relatively large exchange bias might still result from frustration in the F thin film of exchange coupling to differently oriented nanometer-sized AF twins. By extension from the study of the untwinned sample (sample u-AF), half of the twins promote unidirectional and uniaxial anisotropies (in different directions) in the F thin film, while the remaining half will promote only an uniaxial anisotropy in the F thin film. Competition between the formation of different anisotropies over lateral length scales of tens of nanometers may lead to frustration in the F thin film, and concomitant enhancement of exchange bias.
45. The factor of 2/Π is obtained by evaluating the integral representation, (formula presented) of the sum (formula presented)