FN ISI Export Format VR 1.0 PT J AU Pierce, DT Unguris, J Celotta, RJ Stiles, MD TI Effect of roughness, frustration, and antiferromagnetic order on magnetic coupling of Fe/Cr multilayers SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS AB The interplay between interfacial disorder and the antiferromagnetic order in Cr lends to complex behavior in Fe/Cr multilayers. Measurements of interlayer coupling are discussed for samples with different amounts of disorder ranging from optimally fabricated trilayers of Fe/Tr/Fe on Fe(0 0 1) whiskers, to trilayers with increasing degrees of interfacial roughness, and finally to superlattices of Fe/Cr. The coupling of ferromagnets through noble-metal spacer layers can be described by a model that consists of bilinear coupling averaged over thickness fluctuations and extrinsic biquadratic coupling induced by the thickness fluctuations. This, the conventional model, also describes much of the behavior observed for Fe/Cr multilayers. However, in this case, the antiferromagnetism in Cr lends to results not explained by the conventional model. For nearly ideal interfaces, the Fe-Cr coupling can induce order in Cr, modifying the temperature dependence of the interlayer coupling. In addition, interfacial disorder can frustrate the antiferromagnetic order in the Cr, leading to a variety of ordered states which have been observed by neutron scattering. Each of these ordered states, in turn modifies the interlayer coupling in unexpected ways. The different ways in which the systems minimize the frustration can explain the experimental results. (C) 1999 Elsevier Science B.V. All rights reserved. BP 290 EP 321 PG 32 JI J. Magn. Magn. Mater. PY 1999 PD OCT VL 200 IS 1-3 GA 241DP J9 J MAGN MAGN MATER UT ISI:000082867700019 ER PT J AU Schmidt, CM Burgler, DE Schaller, DM Meisinger, F Guntherodt, HJ TI Correlation of short-period oscillatory exchange coupling to nanometer-scale lateral interface structure in Fe/Cr/Fe(001) SO PHYSICAL REVIEW B AB We investigate Fe/Cr/Fe(001) trilayers grown on AE(001)/Fe/GaAs(001) substrates at different temperatures. By changing the substrate temperature of the bottom Fe film during deposition, but otherwise keeping the preparation parameters constant, we are able to tailor the roughness of the Fe/Cr interfaces. The interfaces are characterized by means of scanning tunneling microscopy (STM). In these differently prepared systems, a clear change of the short-period oscillation amplitude is observed by magneto-optical Kerr effect measurements. A statistical analysis of the STM images allows us to extract the lateral length scale over which the Cr thickness is constant, and it turns out that areas of constant Cr thickness with a diameter larger than 3-4 nm are mandatory for the evolution of short-period oscillations. Two mechanisms are discussed which can explain the observed correlation between structure and magnetism, one linked to the propagation of the coupling through the spacer and the other to the response of the ferromagnetic layers to the transmitted exchange field. [S0163-1829(99)04430-6]. BP 4158 EP 4169 PG 12 JI Phys. Rev. B PY 1999 PD AUG 1 VL 60 IS 6 GA 226AA J9 PHYS REV B UT ISI:000081997100063 ER PT J AU Sobolev, VL TI Internal structure of a domain wall in ultrathin magnetic film SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS AB Micromagnetic analysis of a domain wall internal structure in ultrathin magnetic film is carried out. The case when the film thickness is much smaller than the exchange length (the effective width of a Bloch line) is considered. It is shown that in this limiting case the angle of the domain wall twisting is very small and the domain wall has the quasi-Bloch structure. (C) 1998 Elsevier Science B.V. All rights reserved. BP 195 EP 196 PG 2 JI J. Magn. Magn. Mater. PY 1998 PD JAN VL 177 PN 1 GA YZ517 J9 J MAGN MAGN MATER UT ISI:000072262000079 ER PT J AU LABRUNE, M MILTAT, J TI WALL STRUCTURES IN FERRO ANTIFERROMAGNETIC EXCHANGE-COUPLED BILAYERS - A NUMERICAL MICROMAGNETIC APPROACH SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS AB Two-dimensional wall structures in ferro/antiferromagnetically exchange-coupled bilayers are calculated by means of numerical micromagnetic simulations. Extended wall tails occurring in non-compensated structures are duly accounted for via the introduction of a variable meshing along one space direction. Constant charge finite volumes and the application of general boundary conditions in the presence of interlayer exchange coupling and/or surface anisotropy further characterize the computation scheme. Simulated wall structures in zero field are compared with various approximate analytical models and the ranges of validity of the latter are made explicit. Hard-axis field intrinsic magnetization and hysteresis properties are outlined, and a sketch of the wall structure phase diagram is proposed for given material parameters and a specific geometry. BP 231 EP 245 PG 15 JI J. Magn. Magn. Mater. PY 1995 PD NOV VL 151 IS 1-2 GA TJ230 J9 J MAGN MAGN MATER UT ISI:A1995TJ23000038 ER PT J AU HARDNER, HT WEISSMAN, MB PARKIN, SSP TI HISTORY DEPENDENT DOMAIN-STRUCTURES IN GIANT-MAGNETORESISTIVE MULTILAYERS SO APPLIED PHYSICS LETTERS AB Resistance noise measurements of several types reveal the field history dependence of domain structure in sputtered Co/Cu multilayers. We find many smaller domains as the field is decreased from saturation towards zero, but as the field changes sign and is increased in the opposite direction we observe a smaller number of larger domains. Cycling the field without changing its sign preserves the smaller domains, strongly reducing the Barkhausen noise, Discrete fluctuations in resistance due to individual domains yield domain size estimates. (C) 1995 American Institute of Physics. BP 1938 EP 1940 PG 3 JI Appl. Phys. Lett. PY 1995 PD SEP 25 VL 67 IS 13 GA RW225 J9 APPL PHYS LETT UT ISI:A1995RW22500049 ER