Europhys. Lett.
Volume 69, Number 2, January 2005
Page(s) 270 - 276
Section Condensed matter: electronic structure, electrical, magnetic, and optical properties
Published online 17 December 2004
Europhys. Lett., 69 (2), pp. 270-276 (2005)
DOI: 10.1209/epl/i2004-10337-8

Low-temperature microwave emission from molecular clusters

A. Hernández-Mínguez, M. Jordi, R. Amigó, A. García-Santiago, J. M. Hernandez and J. Tejada

Departament de Física Fonamental, Universitat de Barcelona Avda. Diagonal 647, 08028 Barcelona, Spain

received 15 June 2004; accepted in final form 12 November 2004
published online 17 December 2004

We investigate the experimental detection of the electromagnetic radiation generated in the fast magnetization reversal in $\chem{Mn_{12}}$-acetate at low temperatures. In our experiments we used large single crystals and assemblies of several small single crystals of $\chem{Mn_{12}}$-acetate placed inside a cylindrical stainless-steel waveguide in which an $\chem{InSb}$ hot-electron device was also placed to detect the radiation. All this was set inside a SQUID magnetometer that allowed to change the magnetic field and measure the magnetic moment and the temperature of the sample as the $\chem{InSb}$ detected simultaneously the radiation emitted from the molecular magnets. Our data show a sequential process in which the fast inversion of the magnetic moment first occurs, then the radiation is detected by the $\chem{InSb}$ device, and finally the temperature of the sample increases during 15 $\un{ms}$ to subsequently recover its original value in several hundred milliseconds.

75.50.Xx - Molecular magnets.
75.45.+j - Macroscopic quantum phenomena in magnetic systems.

© EDP Sciences 2005