MAGNETORESISTANCE IN NANOSIZE STRONTIUM FERROMOLYBDATE WITH DIELECTRIC INTERLAYERS
| Autor: | Nikolay Kalanda, Aliaksandr Zhaludkevich, I. A. Svito, Nikolai A. Sobolev, M. V. Yarmolich |
|---|---|
| Rok vydání: | 2018 |
| Předmět: | |
| Zdroj: | Izvestiya Vysshikh Uchebnykh Zavedenii. Materialy Elektronnoi Tekhniki = Materials of Electronics Engineering. 19:149-155 |
| ISSN: | 2413-6387 1609-3577 |
| Popis: | Single phase strontium ferromolybdate nanopowder with a double perovskite structure has been synthesized using the citrate gel technique at pH = 4. A superstructural ordering degree of the iron and molybdenum cations of 88% has been obtained. X−ray diffraction of pressed Sr2FeMoO6−δ pellets subjected to annealing at T = 700 K and p(O2) = 10 Pa has revealed the formation of the SrMoO4 phase at grain boundaries. The temperature dependence of the electrical resistivity in the 4.2 to 300 K range changes from a metal type one in the single phase Sr2FeMoO6−δ to a semiconductor type one in the Sr2FeMoO6−δ – SrMoO4 – Sr2FeMoO6−δ structure containing dielectric interlayers, indicating variable charge hopping in the latter structure. In the applied magnetic fields the temperature dependence does not change qualitatively; however, the resistivity decreases with increasing field, i.e., a negative magnetoresistance of up to 41% at T = 10 K and B = 8 T is observed. The external field forms a collinear spin structure, thus increasing the spin−polarized current through the barriers in the granular Sr2FeMoO6−δ – SrMoO4 – Sr2FeMoO6−δ heterostructure. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|