Influence of the K+ ions and the superstoichiometric manganese on structure defects, magneto-transport and dielectric properties of magnetoresistive La0.7Ca0.3-xKxMn1+xO3-δ ceramic
| Autor: | V. K. Prokopenko, Y.V. Didenko, V. Ya. Sycheva, V.A. Turchenko, A. V. Pashchenko, V. V. Burchovetskii, Yu. F. Revenko, N.A. Liedienov, A. G. Sil’cheva, V. P. Pashchenko, Georgiy Levchenko, D.D. Tatarchuk |
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| Rok vydání: | 2017 |
| Předmět: |
010302 applied physics
Materials science Physics and Astronomy (miscellaneous) Magnetoresistance Analytical chemistry General Physics and Astronomy chemistry.chemical_element 02 engineering and technology Crystal structure Dielectric Manganese 021001 nanoscience & nanotechnology 01 natural sciences Dielectric spectroscopy Lattice constant chemistry Vacancy defect 0103 physical sciences Dielectric loss 0210 nano-technology |
| Zdroj: | Low Temperature Physics. 43:1076-1085 |
| ISSN: | 1090-6517 1063-777X |
| DOI: | 10.1063/1.5004451 |
| Popis: | The structure, its defects, nanostructural clustering and functional properties of the La0.7Ca0.3-xKxMn1+xO3-δ ceramic with x = 0–0.3 have been investigated by x-ray diffraction, thermogravimetric, SEM, resistance, magnetic, magnetoresistance and dielectric spectroscopy methods. We establish that the lattice parameter of the cubic structure increases when the Ca2+ ions are substituted with ions of K+. We show that the real perovskite structure contains different valence states of manganese MnA2+,MnB3+ and MnB4+ in A- and B-positions, as well as vacancy type point defects, in the form of anionic V(a) and cationic V(c) vacancies. The increase in the content of the superstoichiometric manganese is connected to the nanostructured clustering process. We find that K+ and superstoichiometric manganese cause the increase in relative permittivity e′ and dielectric loss tangent angle tg δ. The experimental phase diagram of the magnetic state has been constructed and allows determining the composition of the magneto... |
| Databáze: | OpenAIRE |
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