Abstract
Results of systematic high-frequency electron spin resonance (ESR) studies of Ba3Cr2O8, a weakly coupled S1/2 dimer system, in magnetic fields up to 25 T are reported. Two pairs of ESR gapped modes corresponding to transitions from a spin-singlet ground state to the first excited triplet states with gaps, Δ AB =563 GHz and Δ CD =399 GHz, are revealed below H c1=12.5 T. The detection of the ground-state excitations by means of ESR clearly indicates the presence of a non-secular term allowing these transitions. A complex structure of the microwave absorption spectrum in magnetic fields above H c1 is observed, those peculiarities are discussed.
Original language | English |
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Pages (from-to) | 231-235 |
Number of pages | 5 |
Journal | Journal of Low Temperature Physics |
Volume | 170 |
Issue number | 5-6 |
DOIs | |
State | Published - Mar 2013 |
Funding
Acknowledgements We thank O. Cepas and J. Deisenhofer for helpful discussions. This work has partly been supported by the DFG and EuroMagNET II (EU contract No. 228043). A portion of this work was performed at the National High Magnetic Field Laboratory, Tallahassee, FL, which is supported by NSF Cooperative Agreement No. DMR-0654118, by the State of Florida, and by the DOE.
Keywords
- Dimers
- Electron spin resonance
- Field-induced phase transition