Regensburg 2016 – wissenschaftliches Programm
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MA: Fachverband Magnetismus
MA 17: Poster Session I
MA 17.19: Poster
Dienstag, 8. März 2016, 09:30–12:30, Poster B1
Magnetic interactions within Fe-Pt nanoparticles — •Svitlana Ponomarova1, Valentyn Tatarenko1, Oleksandr Ponomarov2, Valerii Odnosum1, and Yurii Koval1 — 1G.V. Kuyrdyumov Institute for Metal Physics, Kyiv 03680, Ukraine — 2IntroPro LLC, Kyiv 02140, Ukraine
As well known, magnetic and other material properties are very sensitive to the size of their particles, to their organization when they are non-isolated, and to the chemical content and spatial order. The binary Fe-Pt alloys exhibit high magnetic anisotropy in their ordered L10 phase with high coercivity, good mechanical properties and excellent chemical stability. In present work, calculation of parameters of exchange interactions within the magnetic Fe-Pt nanoparticles for the platinum content range of L10-(super)structure existence (35-55 at.% Pt) have been estimated. The Heisenberg model for the system of randomly located spins, concerning 'slowly'-relaxing arrangement of their atomic carriers in a lattice was updated for binary solid solutions, which consist of two magnetic components (Fe and Pt). Strict dependence between the Curie temperature and the nanoparticles' size was taken into consideration in frame of the finite-size-scaling theory. Available experimental and theoretical values of magnetic moments showed that the most appropriate set of spin numbers is sFe=3/2 and sPt=1/2. Decreasing of magnitudes of exchange interaction parameters was obtained with rising of nanoparticles size. Temperature dependences of spontaneous magnetizations for Fe and Pt subsystems of nanoparticles with different sizes at fixed equiatomic composition are obtained.