Amigo, R.Hernández Ferràs, Joan ManelGarcía Santiago, AntoniTejada Palacios, Javier2010-01-252010-01-2520030163-1829https://hdl.handle.net/2445/10883In this paper we study the effect of microwave absorption on the quantum relaxation rate of Mn12 molecular clusters. We have determined first the resonant frequencies of a microwave resonator containing a single crystal of Mn12-Acetate and measured initial isothermal magnetization curves while microwave power was put into the resonator. We have found that the tunneling rate changes one order of magnitude for certain frequencies. This suggests that the microwave shaking of the nuclear spin and molecular vibrational degrees of freedom is responsible for the huge increasing of the tunneling rate.3 p.application/pdfeng(c) The American Physical Society, 2003MicroonesAbsorcióPropietats magnètiquesRelaxació magnèticaEfecte túnelMicrowavesAbsorptionMagnetic propertiesMagnetic relaxationTunneling (Physics)info:eu-repo/semantics/article514389info:eu-repo/semantics/openAccess