Dept. of Solid State Phys., Univ. of Min. & Metall., Cracow, Poland.
From monoatomic multilayers to ordered alloys.
Inst. Phys. Polish Acad. Sci. Acta Physica Polonica A, vol.97, no.1, Jan.
2000, pp.129-39. Poland.
European Conference `Physics of Magnetism '99'. Poznan, Poland. Committee
Sci. Res. Minstr.
Nat. Educ. Polish Acad. Sci. et al. 21-25 June 1999.
Recent progress in UHV preparation and characterization methods have resulted
in a large variety of novel materials. Among them, magnetic multilayers
have become one of the most investigated systems due to interesting phenomena
like oscillating indirect exchange coupling, spin dependent electron transport,
or large perpendicular anisotropies. An attractive possibility given by
molecular beam epitaxy is to grow the multilayer structures on an atomic
scale by the so-called atomic layer deposition. At the low thickness limit,
a multilayer structure, in which a few atomic layers of different metals
are stacked alternately, is expected to be an artificially ordered alloy.
Such an artificial material, which does not exist in the equilibrium bulk
phase, was constructed for the first time as the AuFe ordered alloy of
the L1/sub 0/ structure. Our conversion electron Mossbauer spectroscopy
studies of this system verified the existence of the tetragonal phase,
which is responsible for the perpendicular anisotropy. The ordering process
is influenced by the complicated growth of Fe on Au, as shown by the atomic
scale scanning tunneling microscopy investigations. Other systems to be
presented are FeAl (strong ordering mechanism in the bulk) and FeCr (miscible
in the wide concentration range) monoatomic superlattices. (34 References).