| Autor: |
Kumar, Pradeep, Bera, Achintya, Muthu, DVS, Kumar, Anil, Waghmare, UV, Harnagea, L, Hess, C, Wurmehl, S, Singh, S, Buechner, B, Sood, AK |
| Jazyk: |
angličtina |
| Rok vydání: |
2011 |
| Předmět: |
|
| Zdroj: |
IndraStra Global. |
| ISSN: |
2381-3652 |
| Popis: |
Inelastic light scattering studies on a single crystal of electron-doped Ca(Fe0.95Co0.05)(2)As-2 superconductor, covering the tetragonal-to-orthorhombic structural transition as well as the magnetic transition at T-SM similar to 140 K and the superconducting transition temperature T-c similar to 23 K, reveal evidence for superconductivity-induced phonon renormalization. In particular, the phonon mode near 260 cm(-1) shows hardening below T-c, signaling its coupling with the superconducting gap. All three Raman active phonon modes show anomalous temperature dependence between room temperature and T-c, i.e. the phonon frequency decreases with lowering temperature. Further, the frequency of one of the modes shows a sudden change in temperature dependence at TSM. Using first-principles density functional theory based calculations, we show that the low temperature phase (T-c < T < T-SM) exhibits short-ranged stripe antiferromagnetic ordering, and estimate the spin-phonon couplings that are responsible for these phonon anomalies. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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