Tailoring transport properties of phase-separated manganite films with ordered magnetic nanostructures

V. Vlaminck , W. Yánez , Jakobus Hoffman , A. Hoffmann , D. Niebieskikwiat (1)

1 USFQ - Universidad San Francisco de Quito

The magnetotransport properties of thin manganite films (La 0.7 Ca 0.3 MnO 3) coupled with arrays of permalloy (Py) nanodots deposited on the surface of the film is studied as a function of temperature , magnetic field and size of the dots. In the presence of the magnetic dots, a reduction of the electrical resistivity is observed, especially at the insulator-to-metal transition, as well as a shift of the transition peak towards higher temperature. This indicates that, due to the local interface exchange coupling, highly conductive ferromagnetic domains are nucleated in the manganite film underneath the Py nanodots. The use of a simplified resistor network model allows us to estimate the size of the metallic regions induced by the exchange coupling. At low temperatures, these regions extend ∼ 70 nm beyond the edge of the nanodots, a lengthscale comparable to the correlation length of the ferromagnetic clusters in the phase-separated state of La 0.7 Ca 0.3 MnO 3 .

Domaines: Matière Condensée [cond-mat]; Science des matériaux [cond-mat.mtrl-sci]; Electrons fortement corrélés [cond-mat.str-el]; Autre [cond-mat.other]

V. Vlaminck, W. Yánez, Jakobus Hoffman, A. Hoffmann, D. Niebieskikwiat. Tailoring transport properties of phase-separated manganite films with ordered magnetic nanostructures. Physical Review B: Condensed Matter and Materials Physics (1998-2015), 2016, 94 (6), ⟨10.1103/PhysRevB.94.064404⟩. ⟨hal-02310426⟩