Ferromagnetic film, Curie temperature

Fig. 12. Temperature dependences of the magnetisation one curve typical for ferrimagnetic films, eg, RE-TM or garnets, the other one typical for ferromagnetic Co/Pt multilayers (39). compensation temperature = Curie temperature.

C. High-Curie Temperature(T c) Ferromagnetism in Aggregates and Nanocrystalline Thin Films / 114... 

The magnetic properties of the single ferromagnetic films present in our structures have been intensively investigated [16]. The magnetization measurements do not reveal any thickness dependence of the Curie temperature, Tburie, in the thickness range of dF = 3.3 - 70 nm. It is known, in fact, that rCurie may be a function not only of the Ni content [19], but also of the film thickness... 

Suryanarayanan and Brun (1976) have observed in the X-band paramagnetic and ferromagnetic resonances in EuS. The Curie temperature is 16.6 K, indicating a good stoichiometry for the film. 

Size effects in the films depend essentially on substrate type. Namely, iron epitaxial film crystallizes into body centered structure on Ag(lOO) substrate independently of film thickness. For the films thicker than five monolayers, Curie temperature Tc coincides with its bulk value Tc = 1,017 K) so that ferromagnetic order appears diiT [Pg.68]

Fig. 36. Temperature dependence of the Dy turn angle as a function of T /T c, where Tc is the ferromagnetic Curie temperature. Shown are bulk Dy Gi e) a 400 A film (triangles) [DyjLu,] (inverted triangles) [Dy Lui2] (open circles) and [DyisILUis] (squares) and [Dy,4 U ] (solid circles).

In the case of Tb (00.1) films (5nm thick) epitaxially and homogeneously grown onto W (110) crystals, Rau and Jin (1988) and Rau et al. (1990) find that at the topmost surface layer a long-ranged ferromagnetic order exists up to a surface Curie temperature of 250 K (above the Curie and Neel points, 220 and 228 K respectively). The results are shown in fig. 9 for electron spin polarization (% as a function of the temperature). Moreover a short-range ferromagnetic order at Tb surfaces extends up to 300 K. 

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