FMR INVESTIGATION OF MAGNETIC ANISOTROPIES IN FE AU SUPERLATTICES/

Fe(xML)/Au(xML) superlattices(1 less than or equal to x less than or e qual to 4, ML: monatomic layer thickness) have been investigated by th e ferromagnetic resonance method at room temperature. It has been conf irmed that out-of-plane anisotropy held H-u shows oscillatory behavior as a function of Fe layer thickness with a period of 1 ML as reported previously from magnetization measurements. In addition, we have foun d that the in-plane fourfold anisotropy held H-2 oscillates in a simil ar manner. The easy magnetization axis for x greater than or equal to 2.25 is Fe [1 1 0] in contrast with the case, of bulk Fe, and the valu es of H-2 show maxima for x = 2.5 and 3.5, suggesting that the atomic steps at interfaces are formed along the Fe [1 1 0] direction. Further more, the interface roughness for x = non-integer causes wide distribu tions of H-u and H-2 compared to those for x = integer with flat inter faces. (C) 1998 Elsevier Science B.V. All rights reserved.