Phase Diagram of Spin States and Magnetic Interactions in Isotope Substituted (Pr,Eu)0.7Ca0.3CoO3
| Autor: | Alexander N. Taldenkov, D. I. Khomskii, S. Jodlauk, L. M. Fisher, K. I. Kugel, A.V. Kalinov, A. R. Kaul, J. Rohrkamp, N. A. Babushkina, O. Heyer, O. Yu. Gorbenko, Thomas Lorenz |
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| Rok vydání: | 2010 |
| Předmět: |
Materials science
Condensed matter physics Spin states Condensed Matter Physics Atomic and Molecular Physics and Optics Thermal expansion Cobaltite Ion chemistry.chemical_compound Magnetization chemistry Electrical resistivity and conductivity Kinetic isotope effect Condensed Matter::Strongly Correlated Electrons General Materials Science Phase diagram |
| Zdroj: | Solid State Phenomena. :465-468 |
| ISSN: | 1662-9779 |
| DOI: | 10.4028/www.scientific.net/ssp.168-169.465 |
| Popis: | The magnetic/spin-state phase diagram of the (Pr1-yEuy)0.7Ca0.3CoO3 series was obtained on the basis of measurements of the specific heat, thermal expansion, magnetization and resistivity. The phase diagram reveals three different states depending on the static distortions (Eu content), the oxygen-isotope mass, and the temperature. The samples with the lower Eu concentrations are ferromagnetically ordered up to moderate temperatures (about 50 K),, most probably, due to the low-spin Co4+ – intermediate-spin Co3+ interaction of the double-exchange type. As the Eu doping increases, the Co3+ LS (S = 0) state becomes stabilized and the magnetic ordering of the Co4+ ions is suppressed up to temperatures well below 5 K, resulting in a low-temperature anomaly in Cp. At higher temperatures, we observe a first-order spin-state transition from the LS to the IS state of Co3+, which is accompanied by a decrease in the electrical resistivity, an increase in the magnetization, and a strong lattice expansion. |
| Databáze: | OpenAIRE |
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