Orbital fluctuations and orbital order below the Jahn-Teller transition in Sr3Cr2O8
| Autor: | Wang, Zhe, Schmidt, M., G��nther, A., Schaile, S., Pascher, N., Mayr, F., Goncharov, Y., Quintero-Castro, D. L., Islam, A. T. M. N., Lake, B., von Nidda, H. -A. Krug, Loidl, A., Deisenhofer, J. |
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| Jazyk: | angličtina |
| Rok vydání: | 2011 |
| Předmět: | |
| Popis: | We report on the magnetic and phononic excitation spectrum of Sr3Cr2O8 determined by THz and infrared (IR) spectroscopy, and electron spin resonance (ESR) measurements across the Jahn-Teller transition, which is detected by specific-heat measurements to occur at T_{JT} = 285 K. We identify the singlet-triplet excitations in the dimerized ground state and estimate the exchange couplings in the system. Moreover, ESR absorptions were observed up to T* = 120 K with a linewidth proportional to exp{-Delta/k_{B}T} and Delta/k_{B} = 388 K indicating a phonon-mediated spin relaxation via the excited orbital state of the Cr $e$ doublet in the orbitally ordered state. In contrast to the expected drastic change of the IR active phonons upon entering the low-symmetry Jahn-Teller distorted phase below T_{JT}, we find an extended regime T* Comment: 4 pages, 4 figures, omissions removed |
| Databáze: | OpenAIRE |
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