Magnetic phase transitions in epitaxial Fe/Cr superlattices

摘要

The surface spin-flop and Neel transitions are examined in Fe/Cr superlattices. The surface spin-flop, originally predicted by Mills (Phys. Rev. Lett. 20, 18 (1968)), is observed in Fe/Cr(211) superlattices with antiferromagnetic interlayer coupling and uniaxial in-plane-anisotropy. The Neel transition (T(sub N)) of Cr is observed in Fe/Cr(001) superlattices, for which the onset of antiferromagnetism is at a thickness t(sub Cr) of 42(angstrom). The bulk value of T(sub N) is approached asymptotically as t(sub Cr) increases and is characterized by a three-dimensional shift exponent. These T(sub N) results are attributed to finite-size effects and spin-frustration near rough Fe-Cr interfaces.