Materials Research Society Symposium Proceedings:
Magnetic phase transitions in epitaxial Fe/Cr superlattices
Eric E. Fullerton, K. T. Riggs, C.H. Showers, A. Berger, S.D. Bader

The surface spin-flop and Neel transitions are examined in Fe/Cr
superlattices. The surface spin-flop, originally predicted by Mills, is
observed in Fe/Cr(211) superlattices with antiferromagnetic interlayer
copuling and uniaxial in-plane anisotropy. The Neel transition (T_N) of Cr
is observed in Fe/Cr(001) superlattices, for which the onset of
antiferromagnetism is at a thickness t_{CR} of 42A. The bulk value of T_N
is approached asumptotically as t_CR inreases and is characterized by a
three-dimensional shift exponent. These T_N results are attributed to
finite-size effects and spin-frustration near rough Fe-Cr interfaces.