Dielectric barrier formation and tunneling magnetoresistance effect in strontium iron molybdate
Abstract
A comparative X-ray diffraction study of the initial single-phase metal-oxide compound-strontium iron molybdate Sr2FeMoO6 ‑ δ (SFMO)-and that subjected to additional isothermal annealing shows that this heat treatment leads to the appearance of a SrMoO4 (SMO) phase. Small-angle neutron scattering measurements indicate that the SMO phase forms a dielectric shell surrounding SFMO grains, which has a characteristic thickness of 2–4 nm and extends above 120 nm. The character of the temperature dependence of the electric resistance corresponds to the metal-type conduction in single-phase SFMO and changes to a semiconductor type in the material with SMO dielectric shells, which is evidence of a tunneling mechanism of charge transfer. This conclusion is confirmed by an increase in the absolute value of the negative magnetoresistance of SFMO due to the appearance of a tunneling magnetoresistance component of the same sign.
- Publication:
-
Technical Physics Letters
- Pub Date:
- June 2013
- DOI:
- 10.1134/S1063785013060199
- Bibcode:
- 2013TePhL..39..552D
- Keywords:
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- Technical Physic Letter;
- Small Angle Neutron Scattering;
- Dielectric Shell;
- Iron Molybdate;
- Small Angle Neutron Scattering Measure