Low-temperature microwave emission from molecular clusters

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

Received: 15 June 2004
Accepted: 12 November 2004

Abstract

We investigate the experimental detection of the electromagnetic radiation generated in the fast magnetization reversal in -acetate at low temperatures. In our experiments we used large single crystals and assemblies of several small single crystals of -acetate placed inside a cylindrical stainless-steel waveguide in which an 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 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 device, and finally the temperature of the sample increases during 15 to subsequently recover its original value in several hundred milliseconds.