| Stearate films with iron ions in various valence states (Fe2+ and Fe3+) were fabricated by Langmuir - Blodgett (LB) method and slow monolayer collapse method. The composition and construction of nanostructures obtained were determined by surface pressure - area (p-a) method and mass-spectroscopy. Magnetic susceptibility of the two types of layered regular structures was measured. It should be noted that the temperature dependence of susceptibility does not show a Curie - Weiss behavior in the range 77 - 300K. In both types of films the low values of effective magnetic moments for both Fe2+ and Fe3+ were found. This can be explained by assuming the presence of low spin configuration of these ions. All anomalies of magnetic behavior are discussed within the framework of the model of film structuring. This process causes strong superexchange interactions of various (ferro- and antiferromagnetic) types. The coexistence of various exchange parameters opens new opportunities to design novel nanomaterials with required properties. |
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