title: Finite-size effect on magnetic ordering temperatures in long-period antiferromagnets: holmium thin films.
abstract: The thickness dependence of the helical antiferromagnetic ordering temperature T(N) was studied for thin Ho metal films by resonant magnetic soft x-ray and neutron diffraction. In contrast with the Curie temperature of ferromagnets, T(N) was found to decrease with film thickness d according to [T(N)(infinity)-T(N)(d)]/T(N)(d) proportional variant (d-d(0))(-lambda(')), where lambda(') is a phenomenological exponent and d(0) is of the order of the bulk magnetic period L(b). These observations are reproduced by mean-field calculations that suggest a linear relationship between d(0) and L(b) in long-period antiferromagnets.
authors.affiliation: Institut für Experimentalphysik, Freie Universität Berlin, Arnimallee 14, D-14195 Berlin, Germany. eugen.weschke@physik.fu-berline.de
authors.forename: E
authors.initials: E
authors.lastname: Weschke
authors.forename: H
authors.initials: H
authors.lastname: Ott
authors.forename: E
authors.initials: E
authors.lastname: Schierle
authors.forename: C
authors.initials: C
authors.lastname: Schüssler-Langeheine
authors.forename: D V
authors.initials: DV
authors.lastname: Vyalikh
authors.forename: G
authors.initials: G
authors.lastname: Kaindl
authors.forename: V
authors.initials: V
authors.lastname: Leiner
authors.forename: M
authors.initials: M
authors.lastname: Ay
authors.forename: T
authors.initials: T
authors.lastname: Schmitte
authors.forename: H
authors.initials: H
authors.lastname: Zabel
authors.forename: P J
authors.initials: PJ
authors.lastname: Jensen