Abstract
Dipolar transitions in the magnetic cluster and its derivative -perchlorate have been studied by coherent-source spectroscopy at frequencies 1.5–33 . Four magnetic transitions are observed between 2 and 4 in and The temperature behavior of the resonance frequencies, linewidths, and intensities identifies them as transitions inside the spin ground state which is split by the crystal field. In both compounds these transitions are characterized by a Gaussian rather than a Lorentzian line shape, which originates from a random distribution of the internal dipolar magnetic fields with a width of approximately 70 mT for and 140 mT for We find an excellent agreement of experimental findings and theoretical description. Several absorption lines are discovered in at frequencies above 15 which could originate from electronic transitions between different multiplets or lattice vibration modes. No corresponding lines are observed in
- Received 7 November 2000
DOI:https://doi.org/10.1103/PhysRevB.63.214411
©2001 American Physical Society