Exchange interaction and magnetic domain formation in periodically inhomogeneous magnetic media

We investigate the formation of magnetic domains in a magnetic trilayer patterned using ion beam bombardment. The system consists of a finite array of in-plane magnetized ferromagnetic Fe elements embedded into an antiferromagnetically coupled Fe∕Cr∕Fe trilayer. Varying the interelement distance, we observe by means of magnetic force microscopy an intriguing transition from individual to collective behavior of the array elements. Above a critical interelement spacing, strong interelement coupling effects are observed, leading to complex correlations between domain structure on individual elements. The mechanism driving these correlations is the formation of domain boundary walls between elements, contrary to the more commonly observed dipolar coupling effects in magnetic arrays fabricated using lithography. Below this critical spacing, the entire array behaves as a single magnetic entity, exhibiting a collective magnetic domain state. The experimental observations can be simulated numerically and explained using an analytical model. The model correctly predicts observed dependencies on interelement distances.

[1]  B. Hillebrands,et al.  Ion-beam induced magnetic nanopatterning of interlayer exchange coupled Fe/Cr/Fe trilayers , 2007 .

[2]  B. Hillebrands,et al.  Micromagnetism and magnetization reversal of embedded ferromagnetic elements , 2006 .

[3]  P. Fischer,et al.  Real space observation of dipolar interaction in arrays of Fe microelements , 2006 .

[4]  B. Hillebrands,et al.  Magnetic patterning of Fe∕Cr∕Fe(001) trilayers by Ga+ ion irradiation , 2005 .

[5]  P. Hui,et al.  Influence of dipolar interaction on small magnetic dot arrays , 2005 .

[6]  B. Hillebrands,et al.  Magnetic patterning of exchange-coupled multilayers , 2004 .

[7]  J. Giérak,et al.  Magnetic interactions in dot arrays with perpendicular anisotropy , 2004 .

[8]  B. Hillebrands,et al.  Control of interlayer exchange coupling in Fe/Cr/Fe trilayers by ion beam irradiation. , 2002, Physical review letters.

[9]  J. Giérak,et al.  Magnetization reversal in weakly coupled magnetic patterns , 2002 .

[10]  E. Tsymbal,et al.  Magneto-dipole coupling in arrays of micron-size rectangular magnetic elements , 2001 .

[11]  Bode,et al.  Real-space observation of dipolar antiferromagnetism in magnetic nanowires by spin-polarized scanning tunneling spectroscopy , 2000, Physical review letters.

[12]  E. Cambril,et al.  Micromagnetism in mesoscopic epitaxial Fe dot arrays , 2000 .

[13]  R. Stamps,et al.  Magnetization processes and reorientation transition for small magnetic dots , 1999 .

[14]  V. Mathet,et al.  Magnetization Reversal in Arrays of Perpendicularly Magnetized Ultrathin Dots Coupled by Dipolar Interaction , 1998 .

[15]  H. Elmers,et al.  Perpendicular magnetization and dipolar antiferromagnetism in double layer nanostripe arrays of Fe(110) on W(110) , 1998 .

[16]  H. Elmers,et al.  NANOSCALE SPATIAL SWITCHING OF MAGNETIC ANISOTROPY IN PSEUDOMORPHIC FE(110) ON W(110) , 1997 .

[17]  C. Chappert,et al.  Anisotropic magnetic coupling of permalloy micron dots forming a square lattice , 1997 .

[18]  W. Zinn,et al.  Magnetic force microscopy of domain wall fine structures in iron films , 1996 .