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New Paper Published in Journal of Materials Science

Charge transfer mechanisms in strontium ferromolybdate with tunneling barriers

Nikolay Kalanda, Marta Yarmolich, Steffen Teichert, Arne Bohmann, Alexander Petrov, Daniel Moog, Sanjay Mathur

Abstract

The single-phase strontium ferromolybdate powder with the double perovskite structure has been synthesized by the citrate-gel method with superstructural ordering of iron and molybdenum cations of 88%. The formation of the SrMoO4 phase on the intergrain boundaries has been determined by means of the XRD studies, the Electrokinetic Sonic Analysis technique, and FESEM investigations of pressed Sr2FeMoO6-δ powders subjected to the isothermic treatment at 700 K and p(O2) = 10 Pa. The temperature dependence of the electrical resistivity in the temperature range 4.2-300 K has a metallic type in the single-phase Sr2FeMoO6-δcompound and the semiconductor type in the Sr2FeMoO6-δ-SrMoO4-Sr2FeMoO6-δ structure with dielectric sheaths. In the latter case, a hopping mechanism of charge transfer is observed. In the applied magnetic field, the temperature dependence does not change qualitatively; however, the resistivity decreases with increasing field, i.e., a negative magnetoresistive effect appears, reaching 43.6% at 10 T and 10 K. The external field forms a collinear spin structure, thus increasing the spin-polarized current through the energy barriers in the granular Sr2FeMoO6-δ-SrMoO4-Sr2FeMoO6-δ heterostructure.

J. Mater. Sci. (2018).

Öffnet externen Link in neuem Fensterdoi:10.1007/s10853-018-2148-0.

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