Europhys. Lett.
Volume 71, Number 1, July 2005
Page(s) 110 - 116
Section Condensed matter: electronic structure, electrical, magnetic, and optical properties
Published online 01 June 2005
Europhys. Lett., 71 (1), pp. 110-116 (2005)
DOI: 10.1209/epl/i2005-10069-3

Non-equilibrium magnetization dynamics in the $\chem{Fe_8}$ single-molecule magnet induced by high-intensity microwave radiation

M. Bal1, Jonathan R. Friedman1, Y. Suzuki1, 2, E. M. Rumberger3, D. N. Hendrickson3, N. Avraham4, Y. Myasoedov4, H. Shtrikman4 and E. Zeldov4

1  Department of Physics, Amherst College - Amherst, MA 01002-5000, USA
2  Physics Department, City College of the City University of New York New York, NY 10031, USA
3  Department of Chemistry and Biochemistry, University of California at San Diego La Jolla, CA 92093, USA
4  Department of Condensed Matter Physics, The Weizmann Institute of Science Rehovot 76100, Israel

received 22 February 2005; accepted in final form 10 May 2005
published online 1 June 2005

Resonant microwave radiation applied to a single crystal of the molecular magnet $\chem{Fe_8}$ induces dramatic changes in the sample's magnetization. Transitions between excited states are found even though at the nominal system temperature these levels have negligible population. We find evidence that the sample heats significantly when the resonance condition is met. In addition, heating is observed after a short pulse of intense radiation has been turned off, indicating that the spin system is out of equilibrium with the lattice.

75.50.Xx - Molecular magnets.
76.30.-v - Electron paramagnetic resonance and relaxation.
75.45.+j - Macroscopic quantum phenomena in magnetic systems.

© EDP Sciences 2005