| Conţinutul numărului revistei |
| Articolul precedent |
| Articolul urmator |
 133 0 |
 SM ISO690:2012KANT, Ch., DEISENHOFER, Joachim, RUDOLF, T, MAYR, Franz, SCHRETTLE, Florian, LOIDL, Alois, GNEZDILOV, Vladimir, WULFERDING, Dirk, LEMMENS, Peter, TSURKAN, Vladimir. Optical phonons, spin correlations, and spin-phonon coupling in the frustrated pyrochlore magnets CdCr2 O4 and ZnCr 2 O4. In: Physical Review B - Condensed Matter and Materials Physics, 2009, vol. 80, pp. 1-12. ISSN 1098-0121. DOI: https://doi.org/10.1103/PhysRevB.80.214417 |
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 Physical Review B - Condensed Matter and Materials Physics |
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| Volumul 80 / 2009 / ISSN 1098-0121 /ISSNe 1550-235X | |
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| DOI:https://doi.org/10.1103/PhysRevB.80.214417 | |
| Pag. 1-12 | |
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We report on infrared, Raman, magnetic susceptibility, and specific-heat measurements on CdCr2 O4 and ZnCr2 O 4 single crystals. We estimate the nearest-neighbor and next-nearest-neighbor exchange constants from the magnetic susceptibility and extract the spin-spin correlation functions obtained from the magnetic susceptibility and the magnetic contribution to the specific heat. By comparing with the frequency shift of the infrared optical phonons above TN, we derive estimates for the spin-phonon coupling constants in these systems. The observation of phonon modes which are both Raman and infrared active suggest the loss of inversion symmetry below the Néel temperature in CdCr 2 O2 in agreement with theoretical predictions by Chern [Phys. Rev. B 74, 060405(R) (2006)]. In ZnCr2 O4 several new modes appear below TN but no phonon modes could be detected which are both Raman and infrared active. |
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| Cuvinte-cheie Spinell, magnetic properties, Pyrochlore |
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