Exchange anisotropy in polycrystalline FeNi∕FeMn films with hysteresis loop asymmetry

The process of magnetization reversal of a FeNi(50A)∕FeMn(50A) polycrystalline film prepared in a magnetic field has been investigated at temperatures ranging from 25to300K. The external field was oriented in the film plane along the easy or difficult axis of the ferromagnetic layer. In the process of magnetization reversal of the film along the easy axis, strong asymmetry of the hysteresis loop is observed together with an exchange shift. As temperature decreases, the asymmetry becomes more pronounced and the shift increases. The field dependences of the magnetization of the film are symmetric and are not shifted when the external field is applied along the difficult axis. The magnetization reversal process is examined on the basis of a model that takes account of the appearance of high-order exchange anisotropy in polycrystalline films. It is shown that the observed strong asymmetry of the hysteresis loop is associated with the formation of a canted phase and the existence of a metastable state. As the ...

[1]  V. Novosad,et al.  Asymmetrically shaped hysteresis loop in exchange-biased FeNi/FeMn film , 2006 .

[2]  D. Dekadjevi,et al.  Experimental method to determine the misalignment of the easy axis of ferromagnetic and antiferromagnetic films in exchange biased bilayers , 2006 .

[3]  R. Miranda,et al.  Origin of the asymmetric magnetization reversal behavior in exchange-biased systems: competing anisotropies. , 2005, Physical review letters.

[4]  K. Temst,et al.  Reversing the training effect in exchange biased CoO/Co bilayers. , 2005, Physical review letters.

[5]  S. Pogossian,et al.  Hysteretic resonance frequencies and magnetization reversal in exchange biased polycrystalline F/AF bilayers , 2005 .

[6]  A. Hoffmann,et al.  Symmetry driven irreversibilities at ferromagnetic-antiferromagnetic interfaces. , 2004, Physical review letters.

[7]  U. Staub,et al.  Quadrupolar, structural, and magnetic ordering inDyB2C2studied by symmetry analysis and neutron diffraction , 2004 .

[8]  A. Hernando,et al.  Large training effects in magnetic relaxation and anisotropic magnetoresistance in nanocrystalline exchange-biasedNi80Fe20/Co−Obilayers , 2004 .

[9]  S. Cao,et al.  Lattice constant dependence of magnetic properties in bcc and fcc Fe x Mn 1-x alloys , 2003 .

[10]  B. Hillebrands,et al.  Induced fourfold anisotropy and bias in compensated NiFe/FeMn double layers , 2003, cond-mat/0307384.

[11]  France.,et al.  Asymmetric magnetization reversal in exchange-biased polycrystalline F/AF bilayers , 2003, cond-mat/0311351.

[12]  R. Mattheis,et al.  Kerr observations of asymmetric magnetization reversal processes in CoFe/IrMn bilayer systems , 2003 .

[13]  M. Gillies,et al.  Domain processes in the magnetization reversal of exchange-biased IrMn/CoFe bilayers , 2002 .

[14]  U. Nowak,et al.  Domain state model for exchange bias. I. Theory , 2002 .

[15]  Jun Du,et al.  Magnetic exchange bias enhancement through seed layer variation in FeMn/NiFe layered structures , 2002 .

[16]  D. Lacour,et al.  Domain structures during magnetization reversal in exchange-biased layers , 2002 .

[17]  T. Schmitte,et al.  Asymmetric magnetization reversal on exchange biased CoO/Co bilayers , 2002 .

[18]  I. Krivorotov,et al.  Relation between exchange anisotropy and magnetization reversal asymmetry in FE/MnF2 bilayers , 2002 .

[19]  Miguel Kiwi,et al.  Exchange bias theory , 2001 .

[20]  P. Yashar,et al.  Two-stage magnetization reversal in exchange biased bilayers. , 2001, Physical review letters.

[21]  Chunlin Chai,et al.  The effect of microstructure and interface conditions on the exchange coupling fields of NiFe/FeMn , 2000 .

[22]  L. Shen,et al.  Effect of interface roughness on the exchange bias for NiFe/FeMn , 2000 .

[23]  Joo-Von Kim,et al.  Angular dependence and interfacial roughness in exchange-biased ferromagnetic/antiferromagnetic bilayers , 2000 .

[24]  C. Chien,et al.  Exchange Coupling in Ferromagnet/Antiferromagnet Bilayers with Comparable T C and T N , 1998 .

[25]  T. Ambrose,et al.  Angular dependence of exchange coupling in ferromagnet/antiferromagnet bilayers , 1997 .

[26]  A.M. Choukb.  Effect Of Interface On Exchange Coupling In NiFe/FeMn System , 1997, 1997 IEEE International Magnetics Conference (INTERMAG'97).

[27]  R. Metzger,et al.  TEMPERATURE DEPENDENCE OF THE PINNING FIELD AND COERCIVITY OF NIFE LAYERS COUPLED WITH AN ANTIFERROMAGNETIC FEMN LAYER , 1996 .

[28]  Mark T. Johnson,et al.  Orientational dependence of the exchange biasing in molecular‐beam‐epitaxy‐grown Ni80Fe20/Fe50Mn50 bilayers (invited) , 1994 .

[29]  G. Gorman,et al.  MnFe structure‐exchange anisotropy relation in the NiFe/MnFe/NiFe system , 1991 .

[30]  Parkin,et al.  Unidirectionally biased Permalloy: A polarized-neutron-reflection experiment. , 1990, Physical review. B, Condensed matter.

[31]  Malozemoff.  Random-field model of exchange anisotropy at rough ferromagnetic-antiferromagnetic interfaces. , 1987, Physical review. B, Condensed matter.