Abstract
We have observed hysteresis loops and abrupt magnetization steps in the magnetic molecule , where each molecule comprises a pair of identical spin triangles, in the temperature range 1–5 K for external magnetic fields with sweep rates of several Tesla per millisecond executing a variety of closed cycles. The hysteresis loops are accurately reproduced using a generalization of the Bloch equation based on direct one-phonon transitions between the instantaneous Zeeman-split levels of the ground state (an doublet) of each spin triangle. The magnetization steps occur for , and they are explained in terms of adiabatic Landau-Zener-Stückelberg transitions between the lowest magnetic energy levels as modified by an intertriangle anisotropic exchange of order 0.4 K.
- Received 7 December 2004
DOI:https://doi.org/10.1103/PhysRevLett.94.147204
©2005 American Physical Society